The gravel in my knees was after a bike accident as well! Now i have a nice selection of scars on them - a lovely nickname at school for me was slug knees :roll:
I have had my brother drop a skate board from a second story house on to my foot - resulting in my big toenail eventually falling off.
Again with the brother - he dropped an iron -not hot- on my face and split my lip - i have a scar , but it is not really noticable.
At the front of my old school there were gardens encased in these wooden logs - unknown to me one of them had fallen down and was laying in the path where people walk - splat flat on my face i went as i walked right into and tripped over it - in front of everyone.
I have fallen over during P.E lessons in front of everyone.
Nothing really major though - don't think i could handle major.