Somehow the topic of math had come up while we were on the subway, and I made a comment that you need math for most kinds of science.
Me: "Because you need to do various sorts of calculations in order to figure things out. If you want to be a physicist, or an engineer, or an astronomer..."
Cub (interrupting): "What I want to do is create a giant robot so I can take over the world!"
Me: "You'll need math for that too."
* * *
Shortly thereafter, he was getting overheated, so I let him take off his winter coat. He immediately tried to take off his snow pants as well, but I drew the line at that, telling him I didn't want to have to carry his coat and his snow pants when we changed trains.
Lynxcub (bursting into giggles): "But I wanted to take my pants off as well!"
Me: "You mean your actual pants pants, not just your snow pants? Look around, honey - do you see anyone else on this subway running around in their underwear? No? That is because riding the subway in your underwear is a thing that people generally do not do."
Cub: (laughs so hard he gets hiccups)
(This may seem unrelated to the first bit, but read on...)
* * *
Still on the same subway ride, he started getting hyper at one point and trying to hit me - not in serious aggression, but more like over-exuberant play-fighting.
Me: "Please stop that. I know you have a lot of energy, but there will be no punching."
Lynxcub: "But there will be... defeating the city!"
Me: "Oh? And how do you propose to do that?"
Cub: "With a giant digging robot, which will dig holes all over the city, big enough for people to fall into! But upside down, so that they get their heads stuck!"
Me: "Dare I ask why you want everyone to have their heads stuck in holes in the ground?"
Cub: "Because that way it will be easier for me to shoot them all with a rotating-barrel Nerf gun!"
Me: "And why do you want to --"
Cub (cutting me off): "And -- then I'll have the robot dig a big hole, right in the very middle of the city, which will go all the way down to the Earth's core!"
Me: "Won't that let out a lot of lava?"
Cub: "Yes! That's the whole point! I want to make my very own volcano! And no one will be able to see it coming, because first, I'll distract them all by... (lowers his voice and pauses for dramatic effect, then shouts) running around in my underwear!!!"