When you hear something when you're sleeping, it gets memorized and analyzed for you. That's the basis of hypnosis and also the idea around which scientology st

When you hear something when you're sleeping, it gets memorized and analyzed for you. That's the basis of hypnosis and also the idea around which scientology started long ago. It can be used to program an individual, bypassing his critical thinking. Advertisements use the same trick to prime buyers to favor certain brands. If you doubt it, do a simple experiment: record yourself saying something and make the recording play back at night, when you're sleeping.