For the most part, I look back on my decisions with confidence.
The things I regret are usually the possibilities I never considered - things that I could have done to squeeze more out of a particular experience. I tend to try and work out stuff one thing at a time (because my brain can only handle one major worry at a time) which is unfortunate because I'm not making the most of things. This gives me even more pause when reflecting on my present circumstances; I wonder "what am I failing to consider?" and "what else could I be exploring?".