David Lee Roth was in a hotel in Las Vegas and heard Van Halen blasting from a room.  So he knocked on the door . . . but it didn't seem like the guys inside really knew who he was.  It almost seemed that 1.) they were waaaay too inebriated to know what was happening or 2.) They were sure that he was going to yell at them for playing the loud Van Halen tunage.

Credit: TheRothShow via YouTube