This is a repost from a question on Quora (“What does it feel like to attend a world-renowned university?”) that I originally answered in January of 2012. It remains one of my best and most true pieces of writing, so I’ve reposted it here to save it from eventual platform-rot. My experience dates from the mid-2000s.

Going through undergrad at Caltech is the hardest thing you’ll ever do.

Before I can talk about anything else, you have to understand what I mean by this.

Caltech is a place that was built up to take the best scientific minds in the country and push them harder, faster, and further than they’d ever experienced before. It manages this through a couple key points:

• There are almost no introductory classes. The ‘normal’ class track for most majors has you taking graduate level courses starting in your sophomore or junior year.

• The core curriculum requirement is incredible. Every undergrad at Caltech is required to take courses in analysis, multivariable calculus, linear algebra, differential equations, probability and statistics, classical mechanics, special relativity, electricity and magnetism, waves and optics, thermodynamics, quantum mechanics, general chemistry, physical and organic chemistry, chemistry lab, a second lab class chosen from the likes of nanofabrication labs, physics labs, etc, the biology and biophysics of viruses, and a ‘breadth’ or ‘menu’ course chosen from the likes of introductory astronomy, geology, information science, energy science, etc. Everyone takes all of these. No matter your major. Yes, even the premeds have to pass quantum mechanics.

• You take many, many classes. Taking 5-6 courses simultaneously is considered normal. This doesn’t count any ‘small’ course listings like playing for the athletic teams or somesuch. No, we’re talking 5-6 full-blown, hardcore science courses. Taking anything less, even just 4 courses, makes it difficult to remain a full-time student, and difficult to fulfill all the requirements you need in order to graduate on time. On the other hand, many students find themselves taking 7 courses at once in some terms.

• The classes move extremely quickly. Some time ago, Caltech moved to a quarter system where each quarter lasts 10 weeks. Rather than simply teach less material than a corresponding semester-long course, the professors adopted the policy of just accelerating the coursework so that each quarter-long course covers a full semester’s worth of material.

Add onto all of this what can be a somewhat insular social environment that can be as challenging to deal with as your courses, and you can begin to understand what I’m talking about.

To put things into a Silicon Valley perspective, when I came to Mountain View to start a software startup, I asked around to a lot of the alumni contacts I knew for advice. One thing that was often repeated was the warning that “I’d like to say that starting a startup will be the hardest thing you’ll ever do, but you were an undergrad at Caltech, so I can’t. Instead, it’ll be the second hardest thing you’ll ever do.”

Now for the rest of the experience:

Like many world class universities, the faculty are amazing.

You take courses from people who literally wrote the book in their fields. I won’t belabor this point because by now you’ve seen it reiterated many times in the other answers to this question, but it’s pretty neat, and worth mentioning once.

The laboratory access is unparalleled.

It is literally as easy to get a spot in a world-class lab as walking up to a professor after class and expressing your interest. This includes research gigs at national labs, JPL, and associated research facilities. Almost every single student does some form of research work while at Caltech. Most do research work over the summer—when no classes are offered—but many continue their laboratory involvement full time during the school year, on top of the 5-6 classes they have to take as a full-time student.

The Caltech Honor Code is sacred.

No member of the Caltech community shall take unfair advantage of any other member of the Caltech community.

Every Techer knows those words by heart. The attitude of the honor code permeates the school, and every interaction within it. It is taken so seriously that cheating is almost unheard of, despite take-home midterms and finals (more on this later), and when cheating does happen, investigation and punishment of any offense is left to the undergrads. Specifically, there is a group in the student government called the Board of Control (abbreviated BoC), which is responsible for policing academic dishonesty. Their decisions, though reviewed by the dean of students, are almost always upheld, and may include ‘corrective’ measures that range from nullifying a student’s grade on an offending exam, to nullifying a student’s grade in a class, to placing a student on involuntary leave or even expelling a student outright from the Institute.

Advantages of the seriousness with which the Caltech community takes into mind the honor code include the ease with which students can gain personal keys to buildings and laboratories on campus, and extreme levels of comfort and safety around your fellow students. Though it’s not advised, you can basically leave the door to your room open for hours without being personally present, and expect to find nothing missing or misplaced upon your return.

It is literally a violation of Institute policy to administer a proctored exam.

Midterms and finals are take-home, almost without exception. The only time I ever had an in-class final was for a humanities class where the professor didn’t want us to spend too much time worrying about the final paper. He walked in the door, wrote the prompt on the chalkboard, told us we had two hours to write and after that, he’d be back to pick up the papers, and walked right back out the door again.

Take-home exams include specified time and resource limits. For example, they might say “This exam must be taken in four hours, in one sitting, and you may only reference your own hand-written course notes.” or “This exam may be taken over the course of six hours, with a single thirty-minute break not counting against that time limit taken at any time. This exam is considered closed-book, and you may not reference any outside materials.” The worst exams, though, have descriptions that go like this “This is an ‘infinite-time’ exam. You may work on this exam throughout the entirety of finals week, but must turn it in at 5pm on the last day of the week. You may reference anything you like, including any textbooks, Google, or other internet resources, but you may not discuss problems on this exam with anyone else.” Infinite-time, open-Google exams are legendary and terrible, because the more resources the professor has made available to you, the more you can be sure that those resources won’t help you. It’s not uncommon for professors to put open research problems in the field on exams like this.

Another note about Caltech exams is that often, when professors run out of time to teach additional topics in their courses, they’ll include those topics on the final exam anyway, expecting students to use the open-book policy to learn the topics from the textbook on the fly, during the exam, and to then answer difficult questions relating to them.

Caltech requires its students to take a great number of humanities courses.

Little known in the outside world, Caltech has a significant (12-courses, which averages to one every quarter) requirement in the Humanities and Social Sciences that every student must complete in order to graduate. While you have great flexibility in choosing the individual courses you take, you are required to spread them out among several broad categories. Courses eligible for fulfilling this requirement include—beyond the expected literature, foreign language, history and philosophy offerings—those offered in anthropology, business and economic management, economics, law, and political science. It should be noted that many of the courses offered in these latter categories have a particularly ‘Caltech’ approach, often involving significant levels of mathematical analysis, e.g., game theory in economics courses, or options pricing models in related business classes. Despite the unexpected nature of this requirement, many of the best classes I ever took at Caltech were humanities courses.

Years of the Caltech course load give you an incredible ability to focus and to learn new fields extremely quickly.

Like I mentioned earlier, there are very few introductory classes. Most of the time, you’re dropped into courses alongside graduate students in the relevant fields. The difference is that all the grad students have had lower-level, introductory courses at their previous institutions. The undergrads? Not so much. A consequence of this, and of the often 60+ hours a week of problem sets you have to deal with, is that the only way to survive is to develop an incredible ability to focus on the tasks at hand in conjunction with the ability to rapidly learn new fields. The core curriculum helps immensely here, because through it, every student has some basic familiarity with almost every concept in science.

To put it another way, at Caltech, you spend almost every single day for four (or five, or six, or seven) years straight facing problems that you don’t know how to solve. The idea of being faced with a problem that you don’t understand, then, isn’t a scary thing anymore, and instead becomes familiar. Since giving up is not an option, through such repeated exposure to problems you don’t understand you develop a method of dealing with them. You learn how to break unknown problems up into parts, to categorize and classify them, to make powerful analogies to situations you are already familiar with, to learn to use new techniques and methods of thought, and to invent a hundred crazy approaches in a row when nothing else seems to work. Problems that you don’t, initially, have any clue how to solve are par for the course, for every course, for every problem set.

There is a special kind of intelligence among the undergrads at Caltech.

I hope the idea that Caltech undergrads are extremely focused on scientific fields will come as no shock to anyone reading this. I should stress, though, that that same focus does not imply a corresponding lack of interest in non-scientific fields. Like most schools, students at Caltech have a wide variety of interests, and like most world-renowned schools, students at Caltech take their outside interests very seriously. The result, though, is curious in a way that I suspect is probably only really duplicated at MIT. You see, at Caltech, like many other schools discussed in this question, you often get into fascinating discussions with your fellow students about everything from political events to philosophy to popular culture. However, unlike most other schools discussed in this question, when debate occurs at Caltech, it is a very particular kind of debate indeed. At Caltech, real-world evidence and logical thought processes are of paramount importance in a way that can only be true at a place with such a singular focus on science. Blind conjecture, unfounded assertions, emotional exhortations, or contradictory beliefs will get hounded out faster than a fox at a beagle convention. In many cases, it’s exhilarating. In some, it’s annoying. But it always keeps you on your toes.

The social atmosphere:

There are enough details that go into this to make it worth its own section in my answer.

The house system.

Caltech has no dorms and no fraternities or sororities. Instead, there is the house system. There are eight houses, each of which contains between about 70 and 120 students. The houses have membership rules similar to frats, and select new members from among the freshmen during a week-long event at the beginning of each school year called Rotation. Each house is self-governing, extremely close knit and has its own personality, traditions, and quirks. A recent student experience trip conducted by the Caltech student government found that Caltech’s house system promoted a greater degree of interaction between students of different years than was commonly found anywhere else among the other schools toured across the nation.

Each house organizes social events for its members, sports (and other) challenges against other houses, and parties for the entire campus. It’s often said that Caltech is very much like Harry Potter, except we have eight houses instead of four, and no talking hat.

To get an idea of just how important the houses are at Caltech, consider that alongside class-year reunions, Caltech’s alumni association organizes House-specific reunions for each of the eight houses.

Caltech parties are legendary.

Take two parts brilliant engineers, five parts stressed-out students needing a release, three parts wild and crazy ideas, and one part easy access to money and construction equipment, and what do you get? Students spending months building, painting, and decorating parties for a single wild night. Past parties have included flooded courtyards and floating dance floors, snow machines and giant submarines, huge pyramids, rope bridge entranceways extending out of roof-level stairwell windows, programmable LED nets, fifty feet on a side, underground passages, and more. It’s unbelievable.

Nevertheless, Caltech is extremely emotionally challenging.

Years on end of exposure to the pressure cooker environment, to incredibly challenging work, to all-nighter after all-nighter—the most depressing thing is when your all-nighters are regularly scheduled every week by the dictates of your coursework—to, in a nutshell, an environment where your best is never good enough, because nothing is ever good enough, and you’re running as fast as you can just to barely be able to keep up with everything and you’re desperately hoping that nothing goes even the slightest bit badly—like getting sick for a weekend, or, god forbid, during the week—because then you’ll be forced to play catch-up, and it’s almost impossible to catch up once you’ve fallen behind, and it’s a victory when you get six hours of sleep one night because that’s the most you’ll sleep this week until Saturday, and you’ve just gotten your midterms back, but you can’t relax because you’ve got finals in three weeks, and you’re trying your hardest at your sports practice, but it’s not going so well because you’re sluggish on the court because who has reflexes worth a damn when you’re lucky to average five hours of sleep a night, and the prof whose lab you’re working in expects new experimental results on Monday, and your friend is having a breakdown because of relationship issues that you’re hearing no end of, but you want to help because they’re your friend, and another friend you know is in a serious depression because god damn, the stress level is through the roof, and how the hell are you supposed to finish soldering your project together at five in the morning when your hands are shaking and your vision is blurring, and you can hardly keep your eyes open anymore, and you know that you’ll be sick to your stomach all day tomorrow because that’s what always happens after nights like this.

During my time at Caltech, I knew more than a dozen people who spent time at the local mental health clinic’s suicide watch ward. I would be surprised if any Caltech undergrad never had a friend end up there.

Finally, I should mention that the small size of the school opens up many opportunities.

Because the school’s population is so small (only about 850 undergrads) and so selective, the faculty and administration are incredibly accessible, and treat the students with a great deal of respect. It’s not unusual for a student to be able to schedule a same-day sit down meeting with any member of Caltech’s administration or faculty. Further, students sit on almost every Institute committee, from the search committees for new vice presidents of the institute to the freshman admissions committee and beyond. It’s incredibly easy to make connections to members of the faculty and the administration, and I know many fellow undergrads who have found those connections to be absolutely invaluable.

In conclusion…

While I haven’t discussed every detail and aspect of attending Caltech as an undergrad, I believe I’ve hit on the most important points. I’ve left out innumerable crazy stories and weird traditions (throwing liquid-nitrogen-frozen pumpkins off of the roof of a ten story building on Halloween night, anyone?), as well as some of the finer details of the way the school runs, but I hope I’ve been able to impart some visceral understanding of what the school is like for most of its students.