We will not repent - this is our religion (Full lyrics)
Repenting is an irrational, degrading, and self-abusing thought!
To better understand the implication of regret, and the philosophical reasoning behind that commandment, read this article.
snippet: Perhaps your counterpart would have had a better life than you, in which case the past event was impartially bad. It lead to a life less good than some alternative life would have been. But it wouldn't have been your life. So the alternative would not have benefitted you. It would have made someone else exist in your place.