When I see a bunch of skulls in one place like this, or in the catacombs, it makes me think of the accumulated experience of people. Not because of the brains in the skulls or whatever, but just that each skull represents a single human life. Most of the time these are adult skulls, guessing 30+ years each. That's a lot of living.

I just asked google to solve a couple of problems for me. What is the current population, and how many years do they experience in one hour on the wall clock?

Current world population according to Google: 7.6B How many years in 7.6B hours: 867,579.9

So we are nearly at a point where there are a million years of human live/conciousness/etc experienced every hour.

That's a lot.