Who Made Up the Numbers?

A conversation in a van:

Sam (6-yr-old): What's 30 + 30?

Me: 60.

Sam: No!  I was asking Johno (4-yr-old)!

Me: Oh, I thought you wanted to know.

Johno: Daddy, what is the highest number?

Me: There isn't a highest number.

Sam: (To Johno) I told you!

Me: For any number one more can be added.

Sam: Dad, why did they make so many numbers?

Me: Who is "they"?

Sam: Whoever made up the numbers.

Me: Why do you think some people made up the numbers?

Sam: Because you need them for birthdays.

Me: But why do you think someone had to make the numbers?

Sam: Because somebody had to make the numbers.

Me: What if God made the numbers?

Sam: Did he?

Me: Maybe he did.