if you think about the person you were ten, twenty years ago and think "ugh I was so awful/cringe back then" and feel like you should be ashamed of yourself, don't be. you're comparing a more naive version of you -- who was doing their best with the inputs they were given, and who doesn't exist any more -- with the person you are now, who learned from those mistakes (however belatedly it might've been) and grew. if there's such a difference between those points in your timeline that you feel that strongly about it, that just means you must've grown that substantially since then and are doing that much better. you're allowed to be proud of that! live the best life you can going forward and love the person you are now.
(this is a thought i had after someone said something to me here the other day, to the effect of feeling conflicted about memories of their own past behavior, and i wanted to expand on my reply a bit more generally)