So, TIA, you're saying that it doesn't matter if *Monty knows or not*? Or if the contestant knows that he knows?

If so and you're correct, I have to assume that the plain-English proofs are so badly written that only someone already familiar and at ease with the mathematical proofs can follow and appreciate them. I can't, and I have three degrees. Moreover, many other intelligent people can't either, as the length of the Wikipedia article and of this thread suggests.

Or do you mean to say we non-mathematicians are hopelessly stupid and/or putting you on? If we can't understand your explanations, how do we know you're not the hoaxer?   

And if Monty's knowledge doesn't matter, I'll repeat what I wrote earlier: Which assumptions or statements have I made about possible outcomes are wrong? If switching once increases the odds, why not switching again and again (I realize that's crazy, but it doesn't seem any crazier than increasing the odds by switching once - *if* Monty doesn't know or care.)