Originally Posted by Habitual
When you quit calling your self one?
There is that.
I wouldn't get hung up on the term. I neither call myself an expert or newbie. Say for instance I'm discussing with a client or interviewer what my Linux experience is, I state that it extends back to somewhere in the mid 90s and then proceed to discuss the relevant efforts in Linux which I've accomplished that are germane to the conversation at hand.
I fully admit that there are tons of things I do not know, and may never know. Also there are always new things going on, so the process of having gained experience in Linux over time never stops. Similarly the process of gaining experience with anything interesting to you, never stops.