Changing the past (if possible) would change the present person also and that would bring a whole other set of changes or possibilities in the future. It's best to accept that whatever happened happened, for better or worse, and react to that. The problems arise when those course direction changes are not made. We most adapt, learn, overcome, improve and so forth, that is where better presents and futures start.
I think you're on the right track and your last line...I'd like to see a post on it from you; maybe I'll make a weekend-engagement topic about it.