Before Robin Williams Was Famous, This Happened
I went to broadcasting school in Hollywood, CA from 1985-1987. I'm a huge fan of comedy so I frequented the comedy clubs like the Comedy Store and a smaller venue in Pasadena called The Icehouse which has been the stage for the biggest names in comedy at one time or another. To get to the Icehouse you actually had to enter through an alley in the historic district of downtown Pasadena. Odd but cool.
After one show in 1986 the owner of the club came onstage to thank the crowd for coming and then he pointed our how The Icehouse was a mandatory stop for up and coming comedians by regaling us with a story from the clubs' early days in the mid-70's. He said a lady called to ask who the comics were that would perform that night and the owner told her "A young kid from Indianapolis named David Letterman and a crazy improvisational type named Robin Williams". Apparently, since she wasn't familiar with either of them, her response was "meh, maybe next week". Assuming the lady remembered either of their names after they became famous then she was probably kicking herself.