It's how your brain sees things, on tours with the Army in Bosnia+ Kosovo I did some shows (for local charities) and I did the usual stage hypnosis stuff. I managed to get about 10 people in a deep enough trance (I started with about 40-50) and got them to, perhaps eat a lemon or an onion thinking it was an orange or apple. After the show when I spoke to thwe guys they al said they knew what they were doing but, as I told then it was an apple/orange they belived me. I think it was because as soldiers they were conditioned to carry out commands, and as I was commanding them to do things they were doing them. Armed Forces, Policemen/women, Doctors, nurses and people who work for the common good tend to make the best hypnotic subjects