It is shown, and proven that introverts tend to have fewer, but more trustworthy friends. Extroverts has those too, of course. But introverts usualy only stick to them, and their enviroments.

I feel like I am a bit lucky on my intro/extro sides. I'm tipping more on the introversion and it's the intro side of me I enjoy and gain inner motivation from. So whenever I see people speaking of something personal I usualy go extroverted to look a bit less interested in what he/she is saying.