Sri Sri Ravi Shankar:
Contentment comes with an elevation of your consciousness. It is a higher experience. It comes when you do not dwell on something again and again. That is why in the Patanjali Yoga Sutras, Maharishi Patanjali answers the question, 'How to get Vairagya (dispassion)?', by saying, 'Drishtanu shravikavishaya vitrush’asya vashikara sanjna vairagyam'.
If you keep focusing your mind on all that you have seen, all that you have heard, etc., then you will only get more of that.
In the Bhagavad Gita also, Lord Krishna says, 'Dhyayato vishayan pumsah sangas-teshupajayate. Sangat sanjayate kamah kamat krodho 'bhijayate'. Krodhad bhavati sammohah sammohat smrti-vibhramah. Smrti-bhramshad buddhi-nasho buddhi-nashat pranashyati'. (2.62 & 2.63)
It means: If you keep thinking about food the whole day, then the moment you see food the more you will want to eat, even though you are not hungry. It is only because your mind is dwelling on it. The capacity of our senses to enjoy is limited, but the hunger in the mind is unlimited. When there is disproportion between the mind and the body, there is disharmony.
The needs of the mind and the body are different. If the mind and the body are not in harmony and sync with each other, then it causes a great imbalance. It causes huge embarrassment, and a host of problems follow. These disorders like Bulimia, etc., are the result of all this. So, for contentment the first thing to do is to put a brake on the mind. You have to first decide that you want to put a brake to this (habits or tendencies of the mind). And then, to counter what follows, you have to give it some substitute.
For example, someone has a habit of smoking, and you make them give up smoking. They cannot immediately give it up, you need to offer them some substitute for the smoking. And the best substitute is Sadhana (different pranayamas etc.) By doing sadhana, a different kind of joy rises within. That is what is called Pratyahara.
When the Silver Jubilee celebrations of the Art of Living were happening, Mr. Prasanna and Commodore Rao were active on the field the whole day. They did not have food, they did not sleep. They were working day and night. Other teams too were working very hard. Swami Pragyapadji and others in the Ashram were putting in their heart and soul in the event, because their only goal was to ensure that this particular event has to happen very well. They were putting in their 100% at all times, and did not think about anything else. There was only one thing on their mind and that was that this event has to be finished successfully.
So many times, a deadline for your work brings a different kind of energy from within you. At that time nothing else matters. No sense gratification is an issue then. When there is a dedication in life to do some work, or when there is an emergency to get something done, then all your energies are automatically channelized in the fulfilment of that work. All cravings and aversions simply get subdued automatically. Now you cannot have that all the time. But having a goal or a cause from time to time will help you come out of your hunger for insatiable desires. So, by being one-pointed towards a task or a goal through the help of your Viveka (sense of discrimination) helps.
The second thing that helps here is Sadhana (spiritual practices). And greater than these two is the state of being in utter love. When you are so deeply soaked in love, then you simply do not bother for anything else. In that state, following rules and discipline also does not feel like a burden to us, because our love and dedication is focused towards a goal.