When Melvin was a kid, he didn't take constructive criticism from his father well... So, whenever his father try to teach him something, he'd turn his back on him.
Which used to pissed his father off to the point he would scream at Melvin, "DON'T TURN YOUR BACK ON ME, YOU LITTLE ASS-TWAT!!"
Today, to get back at his dad, he spends nights at the cemetary turning his back to his dad's gravesite.
Do you really think I give a shit at this point, Melvin?