Why is mathematics so universal? One of the best arguments comes comes from John Locke - only he *just* missed it.
Locke argues that objects contain "primary qualities" in and of themselves, which include "figure, number, and bulk" (where bulk is density), as opposed to secondary qualities such as color or pain which are produced in consciousness.
If we remove "bulk" from the primary qualities, we are left with geometry and arithmetic alone - and thus the universality of mathematics is a consequence of figure and number as primary qualities of objects!
Now all that is left to do here is justify the removal of density as a primary quality.
This can be done with butterflies. To us, air is as... air. But to a butterfly - from aeronautical quantities such as Reynolds Number - air is like water. Butterflies swim through air more than they fly through it. Thus the experience of bulk is not universal.
Not to mention, hundreds of years after Locke, we now have particle physics and the relevant destruction of real density.
So there it is.
Another day is upon you my friends. Crunch some numbers. Swim through it like a butterfly.