I don't frequently take the time to feed the trolls, but It's better than what I'm working on right now, and you were rather rude, so...

Most people don't understand or intuit infinity.

Infinity is a great abstraction, and perhaps difficult for anyone but great minds such as yourself to truly grasp. For practical purposes, however, most people DO understand it to mean something to the effect of "bigger than the biggest number I can imagine."

In fact, the parent doesn't understand infinity, because with an infinite number of doors,, the probability that you picked the car is exactly zero, not "vanishingly small",

It's a turn of phrase. I was alluding to its zero-ness. Just in case your autism interferes with your comprehension in the future, sometimes when people write or speak, they use literary devices to add color to what they say. Best of luck with that.

and the odds are not "very, very high" but exactly 1 that you picked a goat to start with.

Once again, allusion. My post might be your first exposure to it, but I didn't invent it.

Stick with about 1000 doors - that usually delivers the intuition without confusing people!

Get real. People can't intuitively imagine one thousand doors any more than they can intuitively imagine infinite doors. Perhaps when I tell you to imagine 1000 doors, you can pull up a room with each of them labeled, clearly in view, but the majority of humans can't imagine more than 6 or 7 distinct things at once. A thousand, a million, infinite, it doesn't matter. They'll use the same machinery to picture it - "a huge number bigger than I can imagine."