You have probably seen a hypnotist approaching his target in a train. He starts a casual conversation and also asks that person which station he is going.
The conversation carries on a while and then the hypnotist asks the person again which station he is going. Most of the people tested could not remember where they are going. They get carried away in the conversation.
Street hypnosis is the use of covert hypnosis. It is a little like magic – instead of using props, the hypnotist uses words to divert a person’s attention so that there is a ‘blind spot’.