Define You Know Where The Door Is Meaning

You Know Where The Door Is
To tell someone to get the hell out cuz they are a Mental Infant. Seriously, some people just need to be told that they are not as smart as the rest of us and that they should just stop wasting everyone's time and get the hell out.

Hey man I just played 100 straight hours of Final Fantasy.
Dude, you know where the door is, now get the hell out
By Wilma