[omginternets]

> You simply cannot fit a larger set in a smaller set.

Just restating this in a different way: hash functions are surjective.

[remram]

That's not what this means and in fact they might not be. It is possible for a hashing functions to have no input that leads to a particular hash (it would still be a hashing function).

[dasyatidprime]

I believe you mean “hash functions are not injective”.

[omginternets]

Yes, thanks for catching that.