That was true for me in high school, but not in college.

At Caltech, it took me about an average of 3 hours to learn the material covered in an hour of lecture. A joke at the time was "one week into the semester, and I'm already 3 weeks behind!"

A friend down the hall could learn a Caltech course in a few hours by flipping through the textbook. I was nowhere near as smart as him.

I very much doubt this, and I'm curious about the truth. I suspect that if you replaced 'smart' with 'well trained' it would be true. No one is born knowing support vector machines, but if you'd previously learned perceptrons and quadratic minimization you could understand them in an afternoon. My guess is that your friend was very very precocious - and well trained.

Now I'm curious. Do you know what he ended up doing?

He's also one of the nicest and unassuming fellows I've known. He's like what people say Woz is like (I've never met Woz).

I think what happened was I "learned how to learn". Part of that indeed was getting better at picking out what to focus on. I don't believe I got any smarter.

It was still a full time job to keep up, though. 33 years after I graduated, I still have "examination dreams" where I attend a class and have no idea what the prof is talking about. Fortunately, these dreams have become less and less frequent over the decades :-) But it was worth it. I'm glad I've never been in combat, I shudder to think about the nightmares vets must suffer.

Surely you've had an experience where something you picked up on a single afternoon had more long term value than an entire course?

The distinction in my mind is the definition of useful. Are we talking useful in careers or useful in life? I took six credits worth of British literature that probably won't be making my code any better, but the influence it had on the way I view the world and make decisions can't be replicated by an afternoon of hacking and Googling.

I feel people who have graduated from college, and have obviously excelled in that environment, fail to realize what it is actually like for other people. Sadly, promoting college as the prescription is even more common than this side of the coin.

Still, the intensity of that course can vary, depending on the number of 'credit hours' it is worth: for example, a one credit class might meet for once a week, whereas a three credit class will meet thrice.

Overall I thought it was great, I learned a huge amount, pushed myself really hard (mentally and physically) and had a hoot of a time socially. I don't regret it for a moment - and not just because it didn't cost me or my parents a penny!

[NB My tax payments have more than repaid the investment made in me.]

Semesters by definition are about 15 weeks long. Some schools (like RIT) operate on shorter quarter schedules of ~9 weeks, but this is definitely not the norm.