FlockOfCats, 
I had a couple things come across my timeline that made me think about how far science, especially space science, has come during my lifetime.
For example, when I was younger, Pluto was not much more than a few blurry pixels of a planet, now it is a richly detailed world (and dwarf planet).
When I was a kid, there were 9 planets, now we know thousands, most exoplanets outside the solar system. Wild to think about. 1/3 🧵