I've gotten much more cautious since I had a fall a few years ago and realized that I'm not so invulnerable now. I was ice skating - I'm a very good skater and grew up on skates around the same time I learned to walk and played on traveling hockey teams my entire youth. Someone fell on the ice and I reached down and was helping them up when my skates slipped out from under me. I fell backwards and cracked the back of my head on the ice. I swear I felt my brain slosh in my head. Luckily no concussion or other injury but since then I've just taken way fewer risks and I don't plan on changing that.