I've found I do this, but the reason I tend to (especially in technical conversations) is to try and establish a shared vocabulary. Often times I find that I understand the words people are saying but not enough of the context. Injecting an example of my own helps anchor the conversation for me and keeps the exchange of ideas going.
I didn't realize until you said it, but yes, I do this for technical discussions too. Sometimes I've volunteered to write up a description of an issue on which I'm knowledgeable but not an expert, and when it comes to write it up, I realize there are subtleties about the situation that I didn't understand. So I just make my best guess as to what I think the situation might be, and post it to people who are the experts, knowing they'll correct any mistakes. It is indeed a much more effective way of getting someone to explain something than going back and forth with questions.
Some of my non-geek friends in a friend circle with quite a few geeks of different flavours call this "geek butt sniffing".
I've been accused of it often, when I meet someone new (who's a geek) and we do what in my head is the "geek subject matter negotiation", where each side narrows down domain expertise and experience by doing a breadth first tree search across all shared geek-domains, followed by a depth first search down the tree paths with significant crossover.
One recovering-geek friend says we're going "Pshhhkkkkkkrrrrkakingkakingkakingtshchchchchchchchcch" at each other before deciding on a conversation topic and speed...
