Well, this was kind of a combination of embarrassing and hilarious.
In eighth grade, I was late to class one day, so I was walking briskly to it. I was turning the corner when my friend, who was quite literally sprinting down the hall, slammed into me at full speed. My binders, books, and papers pretty much exploded into the air, as did his, and I was knocked backwards about seven feet from where I originally was. The hilarious part was, and I still to this day have no idea how I did this, but probably about a hundredth of a second before he hit me, I involuntarily raised my hand, fist formed, into his solar plexus. He laid on the floor for about 30 seconds, unable to breathe. It freaked me out at first but when he regained his ability to breathe, we were both laughing hysterically.