So my "Word of the Year" for 2011 is Cryptomnesia. This is one of the most fascinating things I've read about. Wikipedia:
Cryptomnesia occurs when a forgotten memory returns without it being recognised as such by the subject, who believes it is something new and original. It is a memory bias whereby a person may falsely recall generating a thought, an idea, a song, or a joke, not deliberately engaging in plagiarism but rather experiencing a memory as if it were a new inspiration.
There was a group of guys I played Dungeons and Dragons with when I was around 13-16 years old. One had a drow (dark elf) fighter, and he started a guild that he called "The Order of the Ebon Hand."
Later on, the guy running the game finds out there's a Magic: The Gathering card called... Order of the Ebon Hand.
Anyway, the guy with the guild, he swore up and down he'd come up with the name originally and never seen the card before. What a crazy coincidence, he says.
Later on, he finds some of his old MTG cards and... he owns Order of the Ebon Hand.
Cryptomnesia, baby. It's a crazy thing.
There were some examples of this in the book "The Invisible Gorilla." In one story, a guy who had a very detailed memory about Patrick Stewart eating at the same Legal Seafood restaurant as him... the only problem?
Wasn't his memory.
He tells the story about Patrick Stewart a few times, but then he winds up telling it to the guy who was actually there with Patrick Stewart. Embarrassment ensues.
Interesting concept. Apparently it's quite common. Our memories have all kinds of leaks and holes and faults in them - learning the Cryptomnesia was kind of a landmark moment for me.
More on it at Wikipedia if you're interested. Invisible Gorilla is a good read, too.