Ro: Daddy, can I drive the white car when I’m 55?

me: <thinking hard> Yes, Ro, you can even drive it when you’re 16!

Ro: Dad, I’ll drive it when I’m 16 and then stop the numbers.

me: <after I get that stopping the numbers means not aging any more>: Ro, you can drive the white car anytime you’re older than 16 – like 17, 18, 19, 20, and so on.

Ro: OK, but I want to be 16!

This sort of reminded me of a German joke about a nerdy engineer that goes like this (be warned, German humor is different):

Engineer: Daddy, can I have some vanilla ice cream?

Dad: Roland, you’re 40 years old and an electrical engineer. You can have any ice cream you like: chocolate, strawberry, pistacio, vanilla,…

Engineer: Well, then I don’t want to.

In case you’re still wondering: yes the joke is over.