Ironically, it's the things I didn't do that bring me the most regret. The times when I didn't stand up for something or someone, and took the safe route. Those times I have some regret for.

Breaking an arm, scars, etc- They are unpleasant at the time, but zero long term regret. They are like squares on a quilt that tell a story.

Regret for the things we did can be tempered by time; it is regret for the things we did not do that is inconsolable. -- Sidney J. Harris