This encounter inspired "Before Sunrise." And here's the real tear-jerker: Lehrhaupt would never see the 1995 film because -- unbeknownst to Linklater -- by the time of the film's release, Lehrhaupt had died.
Unlike the fictional "Before" characters Celine and Jesse, Linklater and Lehrhaupt tried to keep their relationship going after their initial meeting in 1989, but "that long distance thing" (as Linklater recently told "The Q&A with Jeff Goldsmith") caused the romance to fizzle, and the two lost touch.
Lehrhaupt died in a motorcycle accident in 1994 at age 24. "Before Sunrise" would start shooting only a few weeks later, but Linklater didn't learn of Lehrhaupt's death until three years ago, when a friend of Lehrhaupt's put the real-life story and the fictional story together -- strangely, much like Celine does in "Before Sunset" -- and contacted Linklater with the sad information to relay. Up until then he had hoped that Lehrhaupt might show up at a screening one day.
Make sure to read the entire story over at Slate.