I have several scars atop my head, including one that has resulted in a very small and almost indiscernible bald spot towards the back of my head - I think it was caused by falling backwards into the corner of a glass case. It could also have been caused by having a giant rock dropped on my head from a fairly high distance. The only other scars I can think of are on my kneecap when I played chicken on my bike with a friend who was also on a bike and one on my shin when I played chicken with a car. Nothing too hideous or special.