Neither of you are correct although the former was further away from the truth. It's funny how people think your mouth and your brain are connected. Anyway, depending on how you smoke it, it wont go to your lungs. If you smoke regularly with your mouth closed, the smoke drifts into your throat but the epiglotis stops it from entering your thorax (the place where your lungs are) If you want to get the smoke in your lungs, inhale with your mouth open.. This causes the air to act like a vacuum and bring the smoke into your lungs.