I think a lot has to do with the way you look at it. Speaking for myself, I know I can look back on my life and think there are things I Shoulda Woulda Coulda do or done differently.
But the ability "look back" comes from the lessons learned, experienced & knowledge gained as well as the overall wisdom gained, based on the choices we have made.
If you spent any time, in thought, about a choice you made, then there is/was a pretty good chance it was the right choice at that time. Few people would consciously make a wrong or bad choice.
I feel regret is to strong of a word, I don't regret my choices, but I do learn from them right or wrong.
Here is an on topic quote:
Most people die of a sort of creeping common sense, and discover when it is too late that the only things one never regrets are one's mistakes. ~Oscar Wilde