Too dumb

I did hypnotism as part of a psychology uni course and it was to look at power if suggestion, memory improvement etc. I remember the lecturer telling us that the people who cannot be hypnotised are those that are too dumb (or too young) to follow instructions and those that are too introspective, who question everything happening to them. I've seen a friend get hypnotised into thinking she was drinking her favourite alcoholic drink and seeing her becoming drunk just on water - we know because we've seen her drunk before. I've also hypnotised a housemate of mine by walking him through a scenario where he was driving a car (he's a car enthusiast) and I got him to keep his arms up way longer than usual and do silly things with it without him objecting or realising. However the power of suggestion via hypnotism can be dangerous. Our lecturer also told us a story where a student was hypnotised because he/she was stressed and was told to relax. The suggestion was to do something he/she had often thought of doing but never had the courage to do so. That evening they found that student almost jumping off a building. Not sure if true story but that was what we were told back then.