a: How big is the universe?
b: Infinite.
a: How do you know?
b: I know because all the data indicates it's infinite.
a: But it hasn't been proven yet.
b: No.
a: You haven't seen it.
b: No.
a: How do you know for sure?
b: I don't, I just believe it.
a: It's the same with love I guess.

Apollodorus