last time I hit my head was about 4 maybe 5 years ago. I was sparring with a guy during a mock tournament in kickboxing. I went to kick him in the head, my foot slipped out from under me and I went down landing on the back of my head. I saw the prettiest of lights, stars, and a kalidescope of colors. I got back up thinking I was ok but I wasnt. I had a concussion