You learn from your mistakes. So why regret something that has lead you to become a better person. Next time you wont make that mistake(hopefully).
But there are those who suggest that dispassionate exposure to data does not lead to true learning in your personal life; that there needs to be some sort of fuel for the engine, and that fuel is regret. Not sure where i stand on this, but I don't think that a blanket statement like 'regret is a waste of time' works. I know I'm going off track here, but say you had comitted a crime, or say you had cheated on your wife...would an emotionless review of those actions with the conclusions " Well, I shouldn't do that again." cover it? Would your spouse, assuming you still had one, see the lack of regret as a possitive or negative sign? I have very few regrets in life in general: I believe that on thw whole, all the decisions I have made have been steps down a path towards making me who I am today, and as I like who I am, and enjoy my life, I don't regret any of those steps from a self-interested point of view. But I have hurt people...some of them a lot...and those I regret whenever I think about them. Some were out of carelessness, some dishonesty, and some selfishness, and my regret has helped fule my desire and effort to lessen those aspects of my character...but the regret stays.
because sometimes there isn't a next time, drewp. if you look at some of the member's responses here... a lot of them are mistakes that can't be made again, so there's nothing to learn from them except... "oops, i f'ed up. now look what i've gotten myself into" or "man, i blew a once in a lifetime opportunity".