Muhammad Ali learned boxing because he wanted to fight whoever stole his red and white Schwinn bicycle.
[Cassius Clay] arrived at the black merchant bazaar upon a new $60 red and white Schwinn. However, after Clay and his friend indulged themselves with free popcorn and ice cream they left the auditorium to find that their bicycles had been stolen.
A tearful Clay was directed to the basement of the auditorium where a policeman was manning the boxing gym. Joe Martin listened to young Cassius boast about a statewide hunt for his precious bike and heard the threats he was making to the thief if he was ever caught.
After a while, Martin asked of Clay, “Well, do you know how to fight?”
Clay quipped back, “No, but I’d fight anyway.”
Martin’s best advice to the hot-tempered preteen was to come back around the gym and learn to fight.