Hahah, that's a popular misconception that people have. Here's the definition of the word explained in more detail.
II. Defining 'Noob'
Contrary to the belief of many, a noob/n00b and a newbie/newb are not the same thing. Newbs are those who are new to some task* and are very beginner at it, possibly a little overconfident about it, but they are willing to learn and fix their errors to move out of that stage. n00bs, on the other hand, know little and have no will to learn any more. They expect people to do the work for them and then expect to get praised about it, and make up a unique species of their own. It is the latter we will study in this guide so that the reader is prepared to encounter them in the wild if needed.




Quite sad actually.
Why don't you just ask him why he uses it so much? He probably just picks the slang up from school cos he hasn't got anything else to do. Yeah, i'm sure his English teacher is very proud of him
lol