Some places, like Rome, old houses and The Breakers can be very rewarding to revisit. Some well-loved old places, like the park where I used to love to go and read in Orlando in the '50s, no longer exist. While I find SIN interesting, I have a friend who grew up in SIN and just hates the massive changes.

I mostly miss the unique "flavor" of different parts of the world. Life, stores, accents, food, even smells, used to be a lot more diverse and interesting than they are now. It will be very curious to see how things continue to evolve.