Son: Mom, when I was watching Smallville they said Einstein.
I frown. : Do you know who Einstein is?
Son looks at me as if I’m daft.: Yeah. It’s the dog from Back to the Future.
I go on to explain about the real Albert Einstein.
Blank look from son.: So, he’s Doc Brown’s dog?
I accept that I’ll have to explain this again in a few years. : Yes.