I've answered this question before on SF-- nothing!
How our lives unfold pleasantly or not and who we become in the process does not have simple one on one cause and effect lines. Like the Carole King song, it is tapestry. Pull a thread or group of them and you could damage parts you're satisfied with and want to keep.
I know few things in my life have been wholly 'good' or 'bad'. Some decidedly unpleasant, but most mixed, bittersweet. My only regrets are times i either inadvertently, or consciously for my own mental had to hurt someone else. I would consider taking the opportunity to at least apologize or make amends to those folks.
I spent a third of my life hyper critical, disapproving and distrusting myself, another third working on myself-- to become more who i wanted to be, living my stated values. This last third i finally am at peace with myself. Why risk that by changing something that was hard to live thru but helped shape who i am now? And if the change meant i would not have had my 3 children, and grandson? I'd rather live the memory of bad choices, than miss out on them!