And we learn math because it helps us think, logic is based off math, even if we didn't know it when we started doing it. Most intros to Philosophy have a large portion of logic, which is a sliver of discrete math. Same reason why they make you learn physics in most science programs is that it helps you learn how to model things better.
Nay...logic existed way before math (not talking about logical symbols), and physics is basically the main branch of science, i.e. all other (real) scientific fields are founded from it.
math existed before human kind. . .even before logic. . .
in the words of my good ol' pal Galileo
"Mathematics is the alphabet with which God has written the universe"
say, a universe without humans, without anything, just being there. . .regardless of our existence, pi will be 3.14159. . .
C^2=A^2+B^2 in a right triangle will hold true
1+1 will still be 2. . .
and Math is the language of physics
physics is the language of chemistry
chemistry is the language of biology
biology is the most boring class you can take
everything else is not science and should be burned