He does not change. The human way of thinking does not alter merely because we have grown from childhood to the adult stage. But when one grows from the animal to man, there is a change of perspective and understanding and the way of thinking itself. The attitude to life changes. The practice of Yoga is an evolutionary process and not merely a physical growth or a quantitative expansion.
Evolution is a very significant term.
It is growth of a very novel type. It is a change in the very substance of what we are. It is a growth from humanity to Divinity. Just as we cannot have at present a clear concept of what God is, or the Goal of life is, we cannot also have an idea as to what stages of Yoga are ahead of us. We have only a slight inkling of what is immediately above us, and not of what is far beyond us.