LogFAQs > #939662443

Going from 100+ doors to 2 doors isn't really the same thing. You were most likely going to pick the wrong door before, and going down to 2 basically reveals the right door, since your first pick was very unlikely to get the right door. There's no reason to not switch after such a huge change in probability.

Going from 3 to 2 doors, you had a pretty high 33.3% chance you were right the first time, and switching is technically a better chance, but you had a decently high chance to begin with, so you are much more likely to be wrong if you switch, compared to the 100 to 2 example.