There are those who claim to regret nothing. Setting aside the discussion whether this is actually possible (which I doubt), I am certainly not one of them. In fact, I regret many things, concerning both things I have done and things I have refrained from doing.
At this point in time, however, I can look back with less bitterness than I used to be able to as regards at least some people.
Still, I miss you, R., T., J., and S.
Post scriptum: I stabbed Christmas in the back, but it took two days for it to die all the same.