Well it wasn't in public but it was in school if that counts
School - I went to go kick a football and I did a back flip, missed that ball completely whilst doing the back flip, stood on the ball and did a front flip and the ball hit my head because I slipped onto the ground after I did the front flip. I also want to say that the only reason I did a back flip was because I slipped on a little patch of ice.
Public - This one is a little harder to remember but it was still rather funny. I went out with this girl and there were these guys trying to pick on her when I went into a shop to get something. I walked back in, bought a banana and threw it at the guys and it hit one of them on the head. After the big fight with me and the guys, I walked away and slipped on the same banana...