Strangely enough, when you get older,
the things you didn't understand when you were a child...
start to make sense.
"When this happened, I should have done that."
"When that happened, I should have said this."
Those types of things.
You start to understand rather than regret.

It may be closer to repentance.
So it may be that I do want to repent and erase the ignorant self from my childhood.
Maybe that's what they mean when they say adults are selfish.