Not smart, I will freely admit. It's a struggle sometimes to come to grips with how dumb I've been at times. I console myself with the thought that some people seemingly are unable to consider that they have been wrong/dumb. Regret can be toxic, you can wallow in it, OTOH there is the point of view that inability to feel regret is one sign of sociopathy.
I ran across this lady, Kathy Shulz in a Youtube vid of her Ted Talk: 'Don't Regret Regret:'
https://www.ted.com/talks/kathryn_schulz_don_t_regret_regret?language=en