💡 SCIENCE BEHIND THE ILLUSION:
YES! You MUST switch. Switching doubles your odds of winning from 1/3 (33.3%) to 2/3 (66.7%)! When you initially picked Door 1, you had a 1/3 chance of being right and a 2/3 chance of being wrong. Monty's elimination of a goat shifts the entire 2/3 probability onto the remaining unopened door.