this BBC article today to find out where they are positioned in the history of the world. I entered the world when it had about 1/3 the population it has today. That's a huge change in one not-yet-completed lifetime.
My mom is 92. Her entry point is obviously even further back down the curve:
So, within the sequential lifetimes of just three people, all of this population growth has occurred. That's a staggering thought.