Sounds like you've got a Poem there.
Sometimes it really does hit me, the amount of time that has passed in my life. High School acquaintances? Most of them I haven't seen in about 26 years, since the first and only reunion I went to. A couple of months ago, I had to drop off my car at the shop and then walk to pick up a loaner, and I had to pass by my old High School. I passed a lot of kids on their way home and I kept expecting to see familiar faces-- it was very strange.
Every so often the knowledge of impermanence makes itself known, probably more often as you get older. I find the best cure for that is denial.