Walking along the awnings of the sidewalk, I saw someone else walking down the street in the other direction. He was upside-down too! I waved cheerily and he waved back and approached closer.
When we got into friendly awkward greeting range, I recognized him: my old boss from two jobs ago, a lovable drunk! We shook hands and I asked how he was.
"I've been thinking," he said in his serious, dreamy way, "about Bacon numbers. Eventually, maybe six hundred years from now if you chain generations of actors just right but maybe much sooner than that, there will not be a single living human being with a Bacon number below seven."
I offered him some gum while I thought about that, but some kind of gravity problem happened and the gum ended up on the sidewalk above/below us.
"No," I finally said, staring up at the fallen gum, "that's only true if the movie industry continues in the same format it has right now, which seems unlikely. It could very well be that in thirty years, someone splices together a popular worldwide video, distributed online, featuring every human being, and there will not be a single living human being with a Bacon number above one. Even more likely, the idea of a Bacon number will cease to be computable. Or maybe it will just stop being interesting."
I didn't even get started about the definition of a living human being. I was pondering asking him about Erdős numbers, but decided against it. We shook hands and said goodbye.