I don’t know if it is because I have reached a certain age and look back over a longer sweep of time, or because my children have reached a certain age and I see things differently through their eyes, but I’ve really begun to notice how much things change. I’m only 45 years old, but more and more when I tell my 6- and 8-year-olds about scenes from my childhood I find myself having to explain how things were back then.