Maury Ginsberg was a spotlight operator for tower three at the famous Woodstock music festival in New York on Earth in 1969. After his van died and was dragged off the road, because it was blocking traffic for miles, he hitched a lift to the concert and noticed a disconnected cable that could have ruined the event. He was not aware that the man who drove him there was the member of the Q Continuum later known as Quinn.
Following the concert, Ginsberg went on to meet his future wife, a "groovy chick with the long red beads" that was in the backseat of Quinn's jeep. He then went on to become a successful orthodontist, settle in Scarsdale, and have four children.
Ginsberg was brought aboard the USS Voyager by Q in 2372 along with Sir Isaac Newton and Commander William T. Riker to provide evidence of Quinn's influence on history. He was returned shortly afterwards with no memory of this. (VOY: "Death Wish")