Usually when I see them I kinda wonder where they went unless I read their LJ. Then I think that I hope they talk to me. After that I think that maybe I should try to talk to them because they might not remember right away or be afraid to send a PM or something. So after that it all comes down to awaiting anxiously for them to reply to see if I get a hello, or a how are you let's talk about X, or maybe they will tell me where they went. Oh, it's terrible. I don't think it's happened before.