Earlier quoted context omitted.
"I find that the major objection is that people think great science is done by luck. It's all a matter of luck. Well, consider Einstein. Note how many different things he did that were good. Was it all luck? Wasn't it a little too repetitive? Consider Shannon. He didn't do just information theory. Several years before, he did some other good things and some which are still locked up in the security of cryptography. H…
There was a lot of luck in Facebook, even if Zuck is a particularly talented individual. Also - if Harvard is a great school - how the F does someone find time to do the work and make a product at the same time? When I did Engineering, I didn't have time to take a shower.
I spent way too much time worrying about grades. I'm not sure it mattered. It would have been just as good (and probably more enjoyable) to be a B-student with awesome side projects rather than an A-student with none.
(And often, esp. for college, one doesn't even need to make that trade-off when homework is largely immaterial, and your grade only depends on exams.)