Maybe not fandom - but spend a night talking with a friend and then realize you long for something you haven't read, watched, listened to, or played in forever?
I spent a few hours talking Wing Commander over with a friend. I've currently got the music from a fan game (A FAN GAME, GUYS) downloaded and realizing... how much I missed the well-thought out series it was.
Star Wars is more the people who make up the world. The world of some universes though is- astounding.
I'm hoping to give the gameplay of Wing Commander, The Darkest Dawn, a poke tomorrow. All I know is firing your guns prematurely will get you escorted back to the hangar with a lecture about following orders.
I might try to get myself sent back home to see what that's like...