I did it for fun.
When I was in elementary school, I was suspended a great deal of the time for fighting or committing other violent acts. This lessened as I grew older, but did not completely stop until around high school, where I began to care less and less about violence. One of my most memorable fights was when I was in the fourth grade, an older kid tried to jump me from behind (literary, I supposed), so I flipped him over my shoulder and started beating the :bou::bou::bou::bou: out of his head with all of my limbs. He, uh, left me alone after that.