Here's what doesn't make sense. You decide on a door to open. 1. Okay. Then 3 opens. Goat. You switch. 2/3 chance of car.

Now let's say we go back in time to the moment you picked 1 and picked 2 instead. 3 opens. Goat. You switch. Would it be 2/3 chance or 1/3 chance?? Surely you can't say that it would be 2/3. None of the items have moved since you went back in time.