Araysar, here's the trick to understanding/accepting the monty hall problem:
Imagine playing it with 100 doors instead of just 3. You pick from 1 of 100 doors (99 goats, 1 car). The host then reveals 98 of those. If you picked the car at the start, the other door will be a goat. If you picked one of the 99 goats, the other door will be a car. You'd always switch, right? Well why? Because your odds of picking the right door out of 100 were really low. Well your odds are still less than 50% when there are only 3 doors (it's 1/3). That's why switching doors isn't an even gamble even though there are only two doors left at the end.