Interesting....I myself always stick to a theme, usually butterfly related, and blue, haha. I think that always seemed to reflect me, if anyone was to see a blue girl or a blue butterfly avatar they would connect that to me. I think there are lots of people who are similar in that sense, sticking to a certain theme and such.
I usually end up picturing people as their avatars, mainly when it's a person in it. Even though some people change theirs often (like Nogrod) I just kind of mix all of their previous ones in my head along with their current one. And the avatarless just stay a big question mark in my head, haha.
Makes them very mysterious to me...
Some past ones of mine. The first one being my very first, and probably the one I kept the longest, the other being my previous one. I rather like my current one, I think it will stay a while.