I did the opposite. When I could have taken easy classes I took hard ones. Sometimes I did poorly because I challenged myself so much academically. The result was a mediocre GPA (~3.2). There are a lot of lost opportunities that come with not gaming the system.

I think we have to ask what kind of stupid times we live in when a 3.2 is a mediocre GPA. If you didn't game the system, as you said, to look like "the best of the best of the best", then you suck?

Sometimes our failures guide us. I thought I might want to study mathematics for life. I pushed myself hard and was taking advanced courses. When I received my first bad grade, I realized it was not the right path for me, and that my motivations for delving that far into mathematics were wrong. I'm glad I learned that earlier rather than later.

I've stayed in research, and all those math courses have given me a firm foundation on which to solve real science problems--I see that now. But I cannot regret going through what was fundamentally a learning process, and stepping too far in the wrong direction.

Similar happened, I felt really medicore by (attempting to) studying pure math at one of the top institutes in the world to impress my parents and peers instead of figuring out what truly would want to get me out of bed in the morning.

Same, I was studying theoretical physics in switzerland, and getting paid in gold compared to comparable programs around the world. Within 3 months of starting, I couldnt make myself wake up in the morning, and fell into depression. Leaving the phd, was the hardest decision of my life and give up the wide eyed impressed reactions to the question 'what do you do'. But now (few months later), working in Paris with days filled with novel experiences, makes me glad I didnt hang on and regret it the rest of my life.

I did the opposite too. I kept taking the harder options and while my knowledge and understanding increased drastically.my "GPA" wasn't good enough for anyone. Grass is always greener on the other side heh?

I regret not diving deeper into probability. I find myself wishing I had a stronger handle on advanced probability almost once a month.

I've been trying to catch up somehow but seems like the time is always running away from me.

Probability is hard because it looks simple, but is deeply unintuitive for quite a while.

I write code in my spare time that makes bets in APIs. It's sort of "sports algotrading". As such I care about probability a lot. I found it quite hard to get a grip, and even now I have to hit the books regularly.

It's rewarding, but take it slow and build up. Sometimes you have to treat advanced maths a bit like you would a fitness regime: what does the C25K of the area you're trying to learn look like? Once that's done, what's the 10K version? The half-marathon? The marathon? And so on.

Everybody starts by getting off the couch though - even if you're working through basic probability classes on khan, you're one step ahead of the you that carried on messing about on HN or Reddit or whatever.