It fascinates me how much can happen and change in one's life. The image that I have of my friends is that their lives remain static until I see them again. Then we check in and it seems as though they have lived a couple of lifetimes since we last met. At least that major events have taken place, either externally or internally, and that they have already absorbed them and moved on without my even knowing about the events.
As they say, "A rolling stone gathers no moss."