A research and informationgeek.
Librarians desire to make the whole world of information available to people at the time they need it. Frustrated by the lack of interest in anything more complex than Britney Spears' bust size, some librarians withdraw into an autistic fantasy where everything is perfectly organized. Others catch unsuspecting researchers and brain-dump the contents of the British Library on them. Generally possessed of insane amounts of patience, as Garrison Kiellor pointed out.
"If television is a babysitter, the internet is a drunk librarian who won't shut up." -- comic caption