Scene: playing with Lego. He has built a Lego spaceship, and populated it with a couple of minifigures, one one of whom he declares to be Princess Leia from Star Wars, and the other to be a doctor. The doctor is there because Leia is sick, and has also, he adds as an apparently afterthought, just given birth to a baby.
Lynxcub: The doctor has special thread!
Me: Special thread? What for?
Lynxcub: For sewing up the hole the baby comes out of!
Me: Uh, honey? Babies usually come out of the mama's vagina. That doesn't need to be sewn up, It's kind of permanent. (He looks perturbed, as if this doesn't sound entirely right to him.) Well, unless she tears giving birth. That can happen sometimes - that the mama's vagina gets a little tear in it. Then they sometimes get stitches afterward. But it's only the tear that gets sewn up.
Lynxcub: Yes! That's what the thread is for! And for breaking the bag... (stops to think for a moment)
Me: (wondering if he actually knows the word "amniohook") Yes?
Lynxcub: The baby used a sledgehammer!
Me: (collapses into helpless laughter. Finally, when I recover the ability to make words:) That... That's quite the visual, honey! But I have to know: where did the baby get a sledgehammer while it was still in the mama's uterus?
Lynxcub: (in an isn't-it-obvious? tone) He has his very own tool box!
Me: Did you have one of those when you were born?
Lynxcub: I tried that, but it didn't work (breaking the amniotic sac with a sledgehammer, I assume he meant). So then I tried a hammer and even a power drill, but that didn't work either.
Me: Yes, I seem to recall it took a long time for the water to break...
Lynxcub: Yes! But eventually I used... a jackhammer!
Me: (completely loses it laughing. again.)
. . .
Later, we are on the Christie bus, approaching Christie station. As we start to go around the loop by the station...
Me: Just wait... Almost every time I take this bus, someone has parked their car illegally, right where it blocks the bus from being able to get to the station. It doesn't matter how many No Parking and No Standing and even No Stopping signs they put up there, someone is parked there, at least 75% of the time. But this time, I think we might be in luck... (bus stops and honks the horn loudly) Or not. Actually, I think it's more like 90% of the time. Or 99, maybe.
Lynxcub: Why is that car parked there?
Me: I don't know, honey. There are lots of signs telling them not to, but that doesn't seem to be enough to stop them. Maybe there need to be iron spikes sticking up from the pavement or something...
Another passenger: No, no, that would get the bus too.
Me: Good point. Unless they were retractable, but could only be controlled by a special button the buses were equipped with... (I notice the driver is smiling and looks she's having a very hard time not laughing out loud at this conversation) (then, to the Lynxcub:) What do you think, honey? Maybe a tiger trap that the cars could fall into?
Lynxcub: I think they should explode the car!
Bus driver: (completely losing the battle against cracking up laughing) Yeah, I'm for that!