Why do numbers never stop?

Suppose you said that numbers should stop at some value N. N can be huge - more than the number of atoms in the whole universe. Bigger than any number I can name. But I could still say, "What about N+1 - the next number? Surely, that is a number and it is bigger than your N?"

You must agree that I am right and so now we've got numbers going up to N+1.

But then what about N+2, which is also a number and bigger? And then N+3 etc.

It is that "etc" which goes on forever. Just as the number do.

I hope that helps. Infinity is not an easy concept to comprehend and a lot of people have incorrect ideas about it - including some who have studied mathematics.