John Stamos said his "Full House" catchphrase was inspired by the Roy Orbison song, "Pretty Woman." Stamos frequently said "Have mercy!" on the series and the Netflix reboot, "Fuller House." ...

The actor went on to perform the song on at least three episodes on the Full House ABC sitcom, one during Jesse’s (Stamos) 1991 wedding to Rebecca (Lori Loughlin). See the video below.