I was crying my ass off for no reason. What things have you done without a good reason?

Yesterday I got back from a parade and was feeling very sad and depressed. I didn't know why. I just felt like crying and talking about personal problems I have with someone. I'm not that kind of person that will spill his problems to other people. I'm actually the opposite. I like to help people out with their personal problems. I'm usually a happy guy. I don't even know what happened yesterday. I was crying in my room for like and hour or so. I calmed down and went back to doing what I usually do (play video games). I'm afraid I might be going insane.