My Dad was at Woodstock*. He slept through the Who (the band he'd most wanted to see) and woke up for Sha Na Na. Ten years later, when the group had a TV show, he knew one of the members.
* (fun sign of how much things have changed - he hitchhiked there from Kansas and somewhere in Illinois, a middle-aged-but-with-it couple asked him to take their adolescent son to see the show, because they could tell it would be something big. My dad left the show early because the kid stepped on a bottle and had to be taken home. He's told me that the brown acid was really good, until you were told over a loudspeaker that it was poison.)