When I was five, I decided to play popcorn stand with my bicycle. I upended it and spun the wheels and gleefully made up a song about making popcorn for the circus.
And then I put my middle finger in the spokes.
And had to go for stitches.
I cried all the way there, not because it hurt, but because we were in public and I had my towel-wrapped middle finger raised high in the air, flipping off everyone we passed, which I knew was Super Bad™.