In 1914, there were two countries in the world that required you to have a passport if you wanted to enter - Czarist Russia and the Ottomans. Anywhere else, you could come and go as you pleased.
Mayors, city council members, and legislators come and go, but neighborhoods don't go anywhere.
Theories come and go, but fundamental data always remain the same.
I like having the dough to come and go as I please.
Empires will come and go. The Soviet Union collapses; China can become a superpower, but 'Blue Peter' stays the same.
Technical problems are like gremlins. They come and go.
Technologies and specific vendors may come and go, but massive cultural transformations and new kinds of relationships? Those don't go away.
