I think it's also just a fundamental misunderstanding of how vastly, hugely, mind-bogglingly EMPTY space is.

I can't even comprehend it, and I don't believe anyone can. Human brains aren't designed for big numbers.

EVERY PLANET in the solar system (plus pluto and the other planetoids) can fit between earth and the moon. And we've had people on the moon! It only took 4 days to get there. Every planet could be passed in 4 measly days. And there's barely anything between them on a normal day.

Between solar systems is even MORE empty. Less things floating around, since most stuff gets caught in gravity wells, and the light stuff gets shoved out to the edge by stellar winds.

Between galaxies is ALSO more empty than between solar systems. Waaaaaay less particulate stuff. Even less that's big like rogue planets.

And then you have things called voids where there's basically nothing. All the galaxies have gathered in filaments that look kind of like soap bubbles, and the voids are the bubble. Nothing inside the bubble. Some bubbles are small, some are huge.

When Andromeda and the Milky Way collide in a few billion years, almost nothing will actually "collide", in fact it's basically only going to happen because of how chance works with large numbers, the space between stars in a galaxy is huge, and all the stars will be whizzing by each other and their gravity wells will interact, but they won't hit each other (except, you know... Statistics and big numbers)

So yeah.

Space is really empty, and big exponents on numbers confuse people.