Asklemmy

For me, it's the sheer scale of celestial bodies.

Our Sun is humongous. UY Scuti's radius is 1700 times larger - 185300 times larger than the Earth's. And then there's TON 618, which has a mass 66 billion times larger than our Sun's.

And even those are barely grains of sand when compared to solar and galactic structures... It is humbling, to say the least.

Edit 2: I deleted the previous edit, because my first observation is correct (scale is maintained when going from comparing radii to comparing diameters...), which is why I have an Arts degree.

If math is actually uncovering fundamental laws of the universe, rather than just describing it at various scales, then there's a chance we can rewrite reality with our own set of rules that would render the current ones incompatible (by Gödel's-IT).

https://en.wikipedia.org/wiki/Mathematical_universe_hypothesis

There are more stars in the visible universe than there are grains of sand on all the beaches in the world.

In chemistry I was taught one carbon atom can exist in at least 12 separate living bodies before it's no longer stable.