It is true that different people will react in different ways to the same suggestion because of their subconscious conditioning or belief. For example, if you go to a sailor on the ship and say to him sympathetically, “My dear fellow, you’re looking very ill. Aren’t you feeling sick? You look to me as if you were going to be seasick.”
According to his temperament he either laughs at your “joke” or expresses a mild irritation. Your suggestion fell on deaf ears in this instance because your suggestion of seasickness was associated in his mind with his own immunity from it. Therefore, it called up not fear or worry, but self-confidence.
The dictionary says that a suggestion is the act or instance of putting something into one’s mind, the mental process by which the thought or idea suggested is entertained, accepted, or put into effect. You must remember that a suggestion cannot impose something on the subconscious mind against the will of the conscious mind. In other words, your conscious mind has the power to reject the suggestion given. In the case of the sailor, he had no fear of seasickness. He had convinced himself of his immunity, and the negative suggestion had absolutely no power to evoke fear.
The suggestion of seasickness to the other passenger called forth his indwelling fear of seasickness. Each of us has his own inner fears, beliefs, opinions and these inner assumptions rule and govern our lives. A suggestion has no power in and of itself except if you accept it mentally. This causes your subconscious powers to flow in a limited and restricted way according to the nature of the suggestion.
Extract from the book “The Power of your Subconscious Mind” by Joseph Murphy