I've personally found that "novices" of certain activities or otherwise often are simply trying to find common ground with those who are more skilled or experienced. The "know-it-all" aspect, in my opinion, comes from them attempting to be seen as equals, or at the very least worth talking to about whatever is going on.

Granted there are some people that simply do it for the attention; most are just trying to find a way to get along with people who have been in the game for a while.