Nearly everybody has something that catches their interest more than it does most others around them. Whether it be cars, firearms, science, etc; they have something where their knowledge goes beyond what most would ever care to know. Now of course who doesn't want to show off their extra trivia knowledge on their favorite subject right? Well sometimes you need to be a bit careful of that, especially when you are running a game.
A problem I've seen on more than a few occasions is a gamemaster who suddenly expect their players to have the same level of knowledge as they do. Or expects them to go out and research that subject until they do. Either for penalizing the players in game because they don't know what pick up trucks have four wheel drive and which ones don't. Or that a type of martial arts is more about grapples and throws than anything else. This gets becomes a double problem when the gamemaster expects them to have this knowledge because their characters do.
Don't do this, really just don't. Not only does it tend to piss off the player and sucks some of their enjoyment out of the game but the other players notice you doing this also. Unless you want to set up a whole 'me vs them' mentality at your game table... which I would never recommend.
Gloss over the details. When they decide to shift their truck into four wheel drive before running through a street full of walking dead guys just let them. It makes for more fun all around and nobody feels like they are being screwed because they don't happen to be as much of a gear head as you. Keep it simple and ignore when things don't match up to reality. Just have a good time.