Aristotle tells us that happiness is not only something that we receive, but it is also something we achieve. Many of us hope that circumstances will line up and deliver us the kind of happiness we desire from our jobs, houses, spouses, or that lucky lottery ticket. Aristotle has a different prescription for true happiness. He agrees that we need some good fortune to be happy, but there is something else that is essential for happiness.
For Aristotle, the life of virtue is crucial for human happiness. Wen we are just, kind, courageous, generous, and wise, we experience deep satisfaction and fufillment that is available in no other way. How do we become this kind of person? For Aristotle, becoming a good person is a lot like becoming good at anything else. It takes practice.
If you want to achieve athletic excellence in a particular sport, you practice, with the right equipment, and with the right coach. Similarly, if you want to achieve moral excellence and be truly happy, you must practice the virtues. Do you want to be generous? Then go perform generous actions and you will become a generous person. To do this, you also need virtuous friends who share your view of the good life; and you need the right coach, a moral exemplar to imitate as you seek to become good. Over time, you develop virtuous habits and when you are truly virtuous, you are generally truly happy.