Do you believe in...?

Lately, DJ has been very interested in what I believe in.

Mom, do you believe in Jesus?
Mom, do you believe in the tooth fairy?
Mom, do you believe in Santa Claus?

But today he asked a question that truly took me by surprise, probably prompted by his recent Super Bowl-watching experience.

Mom, do you believe in Lady Gaga?

We had an interesting talk about how we can be sure she exists, unlike, say, the tooth fairy. I still don't think he bought it.