I've made friends in this game who are in that gray area between "real friends" — the people you know and interact with in real life — and "game friends" — the people you work well with in the game but don't have anything else to do with. These are friends with whom I chat on Skype or swap posts on the forums. We banter about the game, share bits of trivia, and occasionally talk about our lives.
As people usually do, we start from the assumption that the other person is basically like us (what psychologists identify as the "false consensus" bias) in a general abstract way. The other player usually assumes I'm about a guy about his age even though I make no attempt to hide the fact that I'm a woman who's nearly twice that. This isn't generally an issue — I find it rather amusing to be called "dude" and "bro" — until …
When the conversation turns to something that causes me to mention my adult children, I often encounter shock. Even if I've told my exact age at some point, these friends often forget it in the context of the game (which I happen to play as well as anyone of their own generation) and between other topics of conversation. But when I bring up my children they suddenly realize that I'm as old as their parents, and parents aren't usually people you share friends with. After that I see a change creep into their conversation, as I suddenly my age begins to trump our common interests in defining for them who I am. That really does make me feel old in a way that simply accumulating more birthdays does not.