A sickness that puts he state of a normal person being a jackass for a period of time. (root word n00b)
Mustapha the day before n00b flu: Hey, guys, how are ya?
Mustapha infected: OMG U R TEH BEEWOTCH LOL!!!1!!1
When a seemingly normal person develops an obsession with a certain computer game.
You never leave your house! You're on the computer all the time. Dude, you've got n00b flu.
Example of what a person infected with n00b flu might say:
OMG i totally pwned this guy at CS yesterday! he was doing mad hacks, but with my supreme skillz i got a headshot on him like 5 times, ROFL!