Interesting bit about limits, I'm in a similar boat. But beside the social aspect of reaching groups of stronger people, something that changed is that my brain used to grok everything out of the blue, and one day.. it didn't.[0] It's not that things became harder but as if a big wall of confusion appeared, while other were still seeing clearly (or so it seems to my panicked eyes). During the years I managed to climb stairs I couldn't before, so it's not a matter of being able to grok things, but what became out of phase with college level content in my brain that killed any speed.
[0] for instance, I was top of my class not by choice but merely because I enjoyed reading all the things all the time because it was so natural, so pleasurable. That pleasure is far away most of the time now.
The emotional / personal aspect of abuse of "thinking" is also interesting.
No, nothing physical or traumatic. The 'one day' was a figure of speech, it was the post high-school -> college transition. I became too lazy before, college through a lot more stuff at once, and it was more about very abstract principles rather than usual objects. You don't use a function, you imagine all functions on highly dimensional spaces .. also psychologically I wasn't used being behind the pack, stress and negative emotion will make you trip faster.
There's also something about how college material is presented maybe, it's a bit obfuscated behind notations. Or maybe that's just me not being in sync with high level thinking anymore. As a kid I loved all weird notations without feeling lost.
[0] for instance, I was top of my class not by choice but merely because I enjoyed reading all the things all the time because it was so natural, so pleasurable. That pleasure is far away most of the time now.
The emotional / personal aspect of abuse of "thinking" is also interesting.