Who assumes the whole earth would have been flooded? The whole world takes on more information after the nature of the world became known.
Your young child might love you more than anything in the whole world, but might not know the first thing about the size and nature of the world.
If you think that is funny try explaining the existence of the Universe including all the failed universes in the multiverse which must have been to account for the perfect balance of this universe getting the gravitation constant just strong enough to group into planets, stars, solar systems, and galaxies and not too strong to collapse everything?
Scientist say the number of failed universes to statistically explain this one getting it right are in the magnitude of 10 to the power of 123.
I believe the above number is larger than the number of atoms in the known universe.
The probability of disbelief is far sketchier than that of belief.