This is a true story of mine, as absurd as it may be. I got a concussion in 1998 whilst watching... a Bills game. At home. In my living room.
It was a busted play, against Jacksonville IIRC, and Flutie darted into the end zone for the win, and to close out the game. I jumped up off my couch, forgetting that my old house only had 7' ceilings, and that I'm 6'6". I cracked my head on a beam to the extent that (1) I broke a chunk out of the sheet rock, and (2) blood was running down my face from the gash on my head. There's a period of time that I don't remember, and I am unclear of how the paramedics arrived, but I was hospitalized overnight, and I do remember a couple of days of brain fog. I was a little bit dizzy, I could not focus or think very well, and my speech was a little bit off. Plus I had a persistent headache for 3 or 4 days.