If a person is filled by great pleasure, then it’s as if he dissolves in it, being completely overpowered by it and like a robot, ready to do anything this pleasure demands from him. And he cannot do anything against it.
Every person has a certain tolerance threshold or a limit up to which he can withstand pleasure or tolerate suffering. Once the pleasure or suffering exceed that threshold, they can enslave him completely. A person is able to oppose them only within a very narrow range of sensitivity, and even then, he can only do so when he is able to protect himself from them in some way. What is that protection? It’s when he understands that he should not give in to temptation, both from the good side and the bad.
Otherwise pleasure and suffering will overpower him completely because a person is created out of a material whose basis is the will to enjoy. Therefore, it is completely obvious that they can easily do anything to him.
From the lesson on Shamati on 11/19/10
How Do We Find Our Point Of Freedom?