You do not learn unless you have been burned.

Yep, this.

This is very relevant to my personalty at least. I was burned and it forced me to a crossroads between quitting or learning to manage risk and emotions properly so I NEVER felt that margin call feeling again.

I still remember that feeling and every time I want to lose control, it stops me. Humans don't like pain so the brain will stop you from doing something dumb again. It's how we're built.