How is it possible to prove that every circle has an inside and an outside?

Question

I was told that this is some kind of riddle, but I've never heard of this one.

Answer 1

make a huge paper circle and then put something in the inside of the circle and something outside of the circle then the thing inside the circle is the inside and the thing outside the circle is the outside
That's how u prove it. =)

Answer 2

I've never heard it either!