Explaining why Indy doesn't remember the Indian Magic in Raiders
Indiana Jones actually spent a quarter of this movie being under the influence of Kali Ma. Thus, that's like being drunk or asleep. His mind was out of it for half the time he was in that dungeon/ritual place. His subconscious couldn't and wouldn't remember what happened afterwards.
Maybe he also felt some "sleepy/blank mind" side effects even after waking up from the Kali Ma possession - like near the end when he tried to pull out his gun on those two swordsmen and realized he didn't have it.