I think I had told someone I'd give them something before Christmas, and that we could exchange gifts, but I forgot about it because I didn't know anything about what they would like, and I forgot about it. On the last day of the school semester, they gave their gift to me, but I told them I didn't have anything and that I was sorry. Probably not the worst, but its the first shitty thing I remember doing that comes to mind. It wasn't intentional, but I think it still counts. Yeah, I felt pretty guilty after that... my self-esteem took a dip for a day because of it, but I got over it.
What was the most traumatic experience you've had in your life, if you don't mind sharing (Answering is optional, sometimes you just don't want to think about it anymore...)?