The older members of the family have banned you from playing Trivial Pursuit, while the younger members offer bribes for answers they don't know.
When you can visit your mother, who comments that she's trying to write a resignation letter, and you go into the bookshelf, grab a book you haven't read in 25 years, and flip to the page that shows exactly the type of letter she wants. Then go back to reading Feist while everyone else boggles at you.
That you can recite scene, episode, season, and character exposition on your favourite sci-fi chracter from a show that hasn't been on for 12 years -- but have difficulty remembering to get the milk within minutes of leaving home.