Gotta run with Garthanos on this. Most backgrounds seem.. petty. On the one hand, I get that in D&D your character is coming into his or her prime as the adventure starts, not before. Still, if I'm going to write a background, I'd like a mechanic to actively leverage that background to my advantage, even if only once every couple sessions.
F'rinstance, if I spent my early life on the streets stealing to survive, I should be able to steal something - no check required - from time to time because that's what my character does. Not the MacGuffin, obviously, but maybe the merchant's contact list or the key to the cell my friend is being held in. Or if I'm from a noble family I should be able to say (as a player) "My family is famous. That guy recognizes me and is nice to us." I'm not asking for an "I win" button, but at least a reliable gimmick of sorts as an homage to that background.