The fourth agreement — Always Do Your Best — is the one that allows the other three agreements to become deeply ingrained habits. Under any circumstance, always do your best, no more and no less. But keep in mind that your best is never going to be the same from one moment to the next. Everything is alive and changing all the time, so your best will sometimes be high quality, and other times it will not be as good. When you wake up refreshed and energized in the morning, your best will be better than when you are tired at night. Your best will be different when you are healthy as opposed to sick; it will depend on whether you are feeling wonderful and happy, or angry and upset.