I don't really "believe" in regret. At each and every point in my life, I was working with the information I had at my disposal, each information having its own "weight" in my mind. Every mistake I've made has brought some information in my mind that wouldn't have been brought otherwise. Fantasies of "changing the past" are seductive, but ultimately pointless. The only way I could justify having regrets, is reminding…
A regret is a mistake that you don’t want to make in the future only it’s projected into the past. “I regret having done that because if I went back to the past, knowing what I know now, I wouldn’t have done that”
You’re also inviting other people not to regret their choices even when those decisions negatively affect you.