In many cases, the more a person thinks, the less joyful they become. It should not be so. Your mind is just society’s garbage bin. Anybody you come into contact with can stuff something in your head. You really have no choice. Whatever comes in and hits any of the sense organs, whether a vision, sound, sensation, taste or smell gets stored in your mind. So what you call the mind, or consciousness, is the accumulative part of the mind that is subject to the kind of social, religious and cultural situations you are exposed to.
We could split the mind into three parts. The discriminatory dimension of the mind, called the intellect, is the accumulative part that gathers information and awareness, which we call pragna. The very way you think, feel and understand life is just what you have gathered in your head. Whether it is social, religious, spiritual, it doesn’t matter. But all this has comes from outside. It is usually of survival significance only and not of any life significance. Your intellect gives you the ability to recycle the garbage part of it. Your survival on this planet is possible because you are able to discriminate between one thing and the other.
The more intellectual you become, the more you start splitting everything around you. Intellect, or logic, doesn’t allow you to be with any one thing totally. So, you could look at intellect as a wonderful instrument for survival. At the same time, intellect is a terrible barrier for you to experience the oneness of life. Your life can be beautiful only if you know to what extent your logic should go and where it should not go.
All the impressions you have in your mind entered only through your five senses.  Sense perception does not give you the impression of reality, because the senses experience everything in comparison. If you had not seen darkness in your life, you wouldn’t know what light is.  When there is a comparison, there is the possibility of duality.  You can only perceive in parts. So, your perception is in bits and pieces and these may never be whole.
Now if you wipe your perceptions with awareness, this intellect can cut through what is true and what is not true. When your intellect becomes razor sharp, when nothing sticks to it, it doesn’t get attached to anything – it is not identified with anything, it just makes you see everything simply the way it is. It is not influenced by your accumulation; by your identifications; by your emotions.
The whole idea of yoga and meditation is this; if you sit here, your mind is here, you are here. A completely different dimension of existence is experienced once you have cleared a space between you and your mind.