In 2004, I attended the Oscar party for The Lord of the Rings: The Return of the King put on by TheOneRing.net.
Even though it was sold out months in advance, I was able to get a room at the Renaissance Hollywood due to my platinum status with Marriott (ironically gained from many nights staying at the Fairfield Inn in Tewksbury) .
The night before the Oscars, I was at the bar having a drink and got talking to a guy named Chuck Holbrook. I told him some of my interests within filmmaking (cinematography, production management, sound design) and then mentioned I was there for Lord of the Rings. Somehow he got the idea I was the sound designer on Lord of the Rings and started introducing me to other people in the bar as such, despite my denial of the fact.
The following year, I was at the Palm Beach International Film Festival with my dear friend James Marcus (who knew the story above). At the big party opening the festival, James told filmmaker Wendy Dent that I was the sound designer on Lord of the Rings but (and this is the kicker) that I was shy about it and would deny it if asked about it.
Wendy came up to me and said "you were the sound designer on Lord of the Rings?" to which I of course replied "no". Armed with the extra twist of a lie James Marcus had told, she didn't accept this and proceeded to try to convince me that I shouldn't be shy and I should be proud if it. My continued protestations that I was not, in fact, the sound designer on Lord of the Rings only served to encourage her to press me on the matter!
I have yet to pay Mr Marcus back for that simple but clever prank.