A friend of mine, who has never played any RPG and is not particularly knowledgeable about nerd culture, somehow got interested in D&D from some middle-school aged campers at a rock camp where she volunteers. So she went to a bookstore and picked up the D&D 4E player's handbook, then took to Facebook to talk about it.
Brian: You should to to [local mini-con]! I've run games there before, and I might be there this year.
Shauna: I would totally go! I've never played it, so I don't want to slow everyone down but would love to watch. Or play if that's not a bummer...
Brian: Um you can't WATCH, you have to PLAY.
Shauna: ok! I just literally do not know how to play. That was not in my giant book.
Game makers, take note!