
When you're 14, you're invincible. Accidents are what happen to other people and the threat of being injured is just sort of a vague reminder of what could happen if it all goes wrong, which it won't.
John found out this morning that his invincibility is actually limited. He discovered this by brushing his hand against the blade in a table saw that he was using in shop class.
Luckily nine stitches closed up the wounds on his fingers but his pride took a hit as well; he's repeated, on his own, "That's the dumbest thing I've ever done" several times.