Hi TNT -- from your profile, you've been sober a while.
My experience so far is that the periods when I reflect on the past -- maybe to an extent some would call dwelling, but I think just intensely reflective -- they're a way of learning for me. Unfortunately, as an active alcoholic I didn't learn the lessons I should have done from actual experience. So now I have to resolve through contemplation, and often conversation with other alcoholics, what normal people would have resolved on the spot.
It's kind of painful, sometimes. But I don't do it often -- it comes on me in spells. Mostly it's when I notice something in myself or others that I never saw before, and I say to myself, "Self, why didn't you ever understand that before? Oh, because you were always half in the bag. Ok, no more not dealing -- time to think about why you turned away from that little part of life." So bit by bit I try to compile all the connections I refused to make before.
Thanks for bringing up this topic.