It isn't. But this is what makes mathematics so full of wonders, literally. You start out with the really simple Peano axioms so that you can do elementary coun

It isn't. But this is what makes mathematics so full of wonders, literally. You start out with the really simple Peano axioms so that you can do elementary counting and somehow it follows that the largest such number happens to be 25 digits long and this particular number. It's the kind of thing where you revert to a three year old and ask: Why? Why? Why?