Famous last words - hindsight is 20/20! Regrets - yes I've had a few (sounds like a song). Many people I've talked to, when asked if they would change anything in their life - pause and answer - "I wouldn't change a thing". That's the easy answer - after all there are plenty of movies about altering time and it's impact later.
Buyer's remorse is another affliction I am doomed to live with. And that remorse is re-enforced every time I see something I have recently bought - go on sale (very ugly for those of us with a frugal gene). And how about those times I conjecture about the opportunity loss of what I could have purchased with the money if only I had not purchased that widget yesterday?
Looking back should only be done with a positive outlook. Al Cambridge the Managing Partner of Cincinnati Accenture taught me this when I would go into his office with my mea culpa. "We are where we are - now let's figure out how we are going to react to this going forward", Al would say.