I heard some guy say that the vaccine knocks out the bodies natural immunity

This is not true. If fact, it's the opposite case: vaccines generate an antibody response, allowing your body to learn how to fight a virus without being exposed to an active virus directly. It's like being taught how to fight with foam-covered sticks before getting in a duel with real steel.

This is also why a vaccine can't help you once you actually get infected with covid (apparently some people thought they could simply delay getting vaccinated until they actually got covid). Once you're in the fight for your life, it is too late to train your immune system in a safe controlled environment.