Is it just spice or is it in response to something?

Like Phineas in Phineas and Ferb...
Some random adult: "Aren't you a bit young to be building a nuclear sub?"
Phineas: "Yes, yes I am."

My son will sometimes say: "I'm age defying."

I tell him that people don't like to hear unsolicited bragging. And we've talked about from how it sounds to him if someone else does similar.