My fucking DAD told me what sounded like a classic urban legend when I was about 18 - I thought it was a bit CHINNY RECKON but I gave him the benefit of the doubt. Until about three years later when I saw Ben Affleck's character say pretty much the exact same story in Good Will Hunting. It's the cop car story - as stolen from reddit:
"The story goes, in short, that Chuck's uncle Marty got pulled over, and during the arresting, there was a car crash down the road. The state trooper tended to the car crash victim, and Marty, instead of taking his own car and fleeing the scene, he takes the state trooper car. The next day, the state trooper find's his uncle Marty and Marty denied the whole thing, until the state trooper took a look in Marty's garage and the state trooper car is in the garage with the lights on."
I highly doubt he's seen Good Will Hunting, so I assume it must just be one of those classic bullshit stories (my generation's would be that gross starburst clusters one).
I wasn't that sad to find out that particular story was bollocks, more that it made me look at a lot of other excellent anecdotes in a different light. My favourite stupid one being that him and his mates had this mutual friend who just went totally AWOL for about 18 months, no phone calls, nothing, until one day he randomly turned up at the house a few of them lived in, came in on a little motorbike scooter thing, did a couple of laps around the table in the front room, then drove off into the night, not to be seen for another couple of years. Richard Edson probably tells the same story in Stranger than Paradise or some shit.