why some people posts so much on facebook? are they self center?

[khongbiet]

[pri✍]

I think the answer is more or less the same as why do you try to labeling people from what they do?

Other than that, it's depends on what they're posting; if they post 'knowledge' such about health matter, security in FB, clearly that's not self centered, but try to spread the knowledge to their friend. Or, will you consider it as show-off? See, you can see everything from opposite angle.