What is universally true is that humans like to create word games ... and play them.

Both of your statements:
"Everything in the universe varies."
and
"No human recognizes a thing devoid of invariants"
are untrue. And the lack of truth in both statements is easily provable.

1. Protons do not vary. At least not within the current age of the universe.
2. I recognize protons.

And if you apply a few synapses you can come up with a near limitless list of other examples.

Far as I know 1=1 hasn't varied recently either.

DA Morgan