There are times I believe there are things I would tell my father now that I couldn't say to him when he was alive. But it's all bravado. I'd probably swallow it as I did then. Come to think of it, there isn't much that's unresolved. Either way the damage is probably done.
I'm from the "don't look back" school. Not that I eschew introspection, it's just better not to dwell.
Besides my memory is so bad I can no longer assign cause to frailty. Who to blame, nature or nurture for a particular shortcoming? Better to live with it.