Sam Guthrie's first big decision as Cannonball is realizing he's working for the wrong person.
In Marvel Graphic Novel #4, he's a Kentucky kid working in a coal mine. His powers emerge during a cave-in, and he gets himself and another miner out. Donald Pierce then recruits him, which puts Sam on the other side from the kids who are about to become his teammates.
He goes along with Pierce until it becomes clear what he's actually being asked to do. Sam won't murder people for him. That refusal is what gets him out of Pierce's operation and into Xavier's school.
It would have been easy to introduce him as the dependable country boy who already knows exactly what he's doing. Instead, he gets fooled. He has to recognize it and make a different choice.
He also comes from a family where money and work aren't abstract problems. Taking a job matters. That makes Pierce finding a way to use him more believable than Sam simply deciding to be a bad guy for an afternoon.
Sam Guthrie's first big decision as Cannonball is realizing he's working for the wrong person.
· Comics / Marvel / X-Men