There was an emotional conditioning song at school: "If you're happy and you know it clap your hands." If you weren't happy (or were happy, but didn't know it), then technically you shouldn't clap, but if you didn't clap you got told off, so you learned to smile and join in and keep the dark thoughts for the bedroom. Anyway, me and Kevin Smith managed to sing "if you're happy and you know it crap your pants" many times, unnoticed, until it caught on and became the accepted chorus. Then, stiff disciplinary measures were taken.