I still wonder today how I got a good certificate on my final exams, considering the fact I was a worthless asshole in highschool and hardly learned AT ALL, moreover, I never did my homework.
But from where I stand today, I think I'm mature enough to say that many of the subjects I learned in school are of no use to me, all those days of studying biochemistry, physics and JAVA; Except some general knowledge, I hardly remember any of it at the moment, and I remember all those times I tried to study those subjects even though I didn't give a SHIT about them. I felt bad back then for failing at some subjects, but today I'd say "screw that, why am I even studying that?"
Well, that's just my feelings.