If you're looking for writing inspiration, it's hard to beat the "Missed Connections" section of Craigslist. Missed Connections is the native country of second thoughts, the forum people use when they've had a close but anonymous encounter with romance, friendship or lust and are hoping to reconnect.
Are you out there, "fast female runner on Waterfront?" Why didn't I get your contact info, "you watching snow in june talking on phone." If this rings a bell - "I gave you a piggyback ride (several weeks ago). Having a hard time getting you out of my thoughts." - then contact me. Browse the site, find a telling detail or a story line that appeals to you, then do a fifteen minute write.