No doubt this is difficult, but at the same time it is simple; and in a small way everyone experiences it, although unconsciously. A person engaged in something that interests him very much, or that completely occupies his mind, is often not conscious of his environment. A poet, a writer, a composer, a thinker, when he is entirely absorbed in something that he does, is unconscious of his environment. And it very often happens that one is so absorbed in something one is doing or thinking about, that one is not conscious of one's body or one's self. Only what a person is thinking of exists for him, not even his self. This is the stage which is termed by Sufis Fana. The word Nirvana about which so much has been said, is simple to understand in this way. It is only an experience of the consciousness; in other words it is the freedom of the soul, reaching a stage where one is not thinking about oneself, nor about one's environment.