I think that is the thing isn't it, the fact that you have time to chat to them and take in that they are in essence some of the nicest people that you have met. And although it is only a few minutes or so that you have known them, your mind seems to take over and tell you that had it been a different time and situation, you would probably have been good friends with them, or liked to have been, so it makes it that little bit harder to stop those "damp eyes"