Charlie David is actually a left-handed golfer but golfed right for the film to appear to be a bad golfer.
The title, Mulligans, is a golf term to refer to getting a second chance to strike a ball in a hole. A golfer would get an extra stroke after a poor shot, and it's not counted on the scorecard.
Prologue: "Mul-li-gans, noun, a mulligan, in golf, happens when a player gets a second chance to perform a certain move or action."