A dog tirelessly gnaws at a bone, the bone wounds its jaws, and the dog, tasting the bleeding of its jaws, assumes that it is the bone that is the source of such taste. In reality, there is nothing in the bone. So too it is with worldly pleasures and experiences. There is nothing in the world. Everything stems from within you. Not knowing that the Source of Eternal Bliss is your own Self, you pursue the world in vain, just like an infant that sucks its thumb assuming it is drinking milk. The pains and pleasures you undergo in this world are not external; they are the result of your own thoughts. When you are happy, the world seems to be a paradise. When you are sad, the world seems a gloomy place. As long as you do not understand this, you are in a state of illusion. Once you comprehend this, you have attained enlightenment.