There's all sorts of conversations like this that are genuinely exciting and fairly profound when you first consider them. Maybe you're older and have had enough conversations about the concept of a singularity that the topic is already boring to you.

Let them have their fun. Related, some adults are watching The Matrix, a 26 year old movie, for the first time today.

For some proof that it's not some common idea, I was recently listening to a fairly technical interview with a top AI researcher, presenting the idea of the singularity in a very indirect way, never actually mentioning the word, as if he was the one that thought of it. I wanted to scream "Just say it!" halfway through. The ability to do that, without being laughed at, proves it's not some tired idea, for others.

I'd be more inclined to let them have thier fun if it they weren't torching trillions of dollars trying to lead humanity into a singularity.