> "Could I have been a decent mathematician if the opportunity was not missed while I was totally unaware of its existence? Obviously there can be no definitive answer to that question."

But there can be a definitive (personal, subjective) answer to the question "why am I torturing myself with resentment over this hypothetical world which never existed? Why does 'being a decent mathematician' have such a hold over me whereas 'being a decent sculptor' or 'being a decent botanist' is emotionally neutral or disinteresting by comparison?

It's quite possible that studying apple tree cultivation and propagation and plant genetics and growth factors could be the most interesting thing you've never been exposed to a good teacher on, and that you could have had a fulfilling and satisfying career doing that, if only, if only.

> "And it’s also ok to be a little resentful of having been tortured for many hours with something that clearly could have been a lot of fun."

Are you equally resentful of being "tortured" with all the other subjects you don't care about and weren't interested in? Does listening to good music make you resentful of your highschool music teacher? Does listening to people speak Spanish make you resentful of your highschool Spanish teacher? Anything "could have been a lot of fun" with the right people, right? Bad days at work can be a lot of fun with a good team and good management but you don't live in resentment every time you go into a shop where the cashier seems happy, going "Imagine how much better my life could have been, I'm full of resentment of the bitchy store manager I worked for at age 18, woe, woe" - not at all.

With hindsight, there was nothing stopping anyone studying math independently in highschool, forming a study group of friends, trying to make it fun, asking other teachers or students, trying to get some money together to pool for a tutor; pinning the next twenty years of resentment on MRS JONES WHO DIDN'T MAKE MATH FUN AND RUINED MY LIFE is a mental behaviour pattern that deserves debugging - or at least noticing - not defending.

You and plonk nailed it. I was being a bit hyperbolic in my original comment; regret is a perfect waste of time. But, as you say, I can't help but wonder how different my life would be had I discovered the joy that is mathematics when I was young.

Similarly, I squeaked out of high school before it was required to learn a second language. At the time I was high-five-ing myself, thinking I'd dodged a bullet. Now, as an adult, I can only begin to imagine how much of the world is closed off to me.