To some degree, we're all thinking about the same things. It's the zeitgeist. The trick, in a way, as a writer, is to hope that your interests in some sense link up with the culture around you.
I find myself thinking more about the past as I get older... maybe because there's just more of it to think about. At the same time, I'm less haunted by it than I was as a younger person. I guess that's probably the ideal: to reach a point where you have access to all of your memories, but you don't feel victimized by them.
There are a lot of writers who find a groove and spend a career mining that vein. I seem to be exactly the opposite.
People define themselves to some degree by the music that they listened to as teens. My mom had Elvis. Me, I had 'The Who' and later punk rock. Kids who came up in the '80s had other songs and bands. It's a way of placing ourselves culturally and temporally.
The sheer sensory experience of San Francisco is unlike anywhere else. Not just the physical beauty, but the textures, the feel, the wind, the ocean. It's a monumental feeling unrivaled by anywhere else. Its a world class, gorgeous city. And the coffee is great.
I did go on safari in Kenya when I was 17, with my mother, stepfather and little brother, and I kept a careful journal of the experience that was very helpful in terms of my sensory impressions of Africa. I have traveled quite a bit at distinct times in my life, though now that I have kids I've settled down.