Supreme happiness is obtained through contentment.
The observances of yoga are the practice of internal and external purity, contentment, mortification, study of scriptures, and worship of God or self-surrender.
You will find in Yoga Vasishtha that Santosha, Santi, Vichara, and Satsanga are the four sentinels at the door of Moksha.
If you have Santosha, the other three will come by themselves. Santosha, contentment, is one of the important virtues for an aspirant.
Riches and poverty are not counted by the amount of wealth one keeps. A king, if coveting too many desires and wants more, is considered to be a beggar. A beggar, if is contented with what they have, is really a king.
From contentment comes real happiness.
If a person has no contentment, their mind will be always wandering. It will be impossible to do concentration and other Yogic practices. Therefore contentment should be developed by all aspirants.