A whole life of regrets

Is that the kind of life you want to lead?
Well, like i wrote in "I wasted one year of my time", it does seem like a whole life of regret.

But honestly, having regrets is a waste of time, and a waste of energy. It is considered a negative emotional state.
Yet, if a mistake has been made, what or how should one feel or do?

I have learnt that it is important to admit your mistake, promise (if not to the other person, than to yourself) never to do it again, and of course keep that promise. While it is "necessary" to feel regret in the initial stages, so that one may move on to the stage of never again doing it, holding onto regrets is not healthy nor needed.

Regrets should energise you to move on and do better the next time. Take regret and transform it into something more positive!