I remember that I had a really short fuse when I was in highschool. One day, I was having a bad day anyway, and a friend of mine made a comment about my appearance. I slapped him. I don't know why I thought it was a good idea. We then got into a fight which ended our friendship. I didn't apologize and haven't had the chance to do so since.
I am still thinking what the friend feels about the situation today and I am ashamed that this happened.