I always wish I had been alive in the 20's when all of the American writers moved to Paris.
Ah, me too. I went to Paris a few years back, looking to stay at Shakespeare and Company (which is a famous bookstore that housed the likes of Hemingway, Allen Ginsberg, Henry Miller, and countless others). I didn't manage to stay there, but I did stay around long enough to understand that I can go to Paris, but I can't go back to Hemingway's time, regardless how hard I try, unfortunately. So it is what it is.
You are so right, you can't chase the ghosts of the past. When I was younger I tended to overly romanticize the past and missed out on a lot of things in present moment.