When someone who was not very committed to Christianity before comes back from Christian camp with a dramatic strong inspiration to live a better life. It often leads to sudden baptisms and preaching to one's friends for a week or two until it wears off.
Matt: "Hey, where's Mike?"
Jim: "Dude, Mike just got home from Christian camp and now he won't smoke or drink with us anymore. He thinks he's better than us or something now. Every time I call him he's at some bible study thing. "
Matt: "Oh see he's got Christian Camp Syndrome... Don't worry he'll be back to normal in a month tops."