I don't know. I regret a ton of small moments, but nothing life changing. I do really regret never writing to my friend Evan after I moved in the 4th grade. He apparently really cared and made sure I had his address and phone number to stay in touch, but I was terrified at the thought of having to talk to his parents (I used to be extremely shy) so I basically snubbed him. Years later I went back to California and went to another friend's birthday party. He had invited Evan and told him I would be there, but Evan never showed. I still don't know if he didn't show because he was mad at me. Makes me sad...