I wouldn’t make the same mistakes I made back then because I’ve learned from those mistakes.
I wouldn’t behave like I did back then because I know my values now.
I wouldn’t be scared of doing those things now because I overcame my fear by doing them then.
Back then I did the best I could, and now, I hope, I would do better.
(And maybe they were doing the best they could do back then too - so maybe they deserve a chance to do better now…)