Because once you have a good life and good friends, things can seem pretty much finished. Unfortunately being finished is rarely enough for people. As humans, we feel an ever-present desire to grow. But to grow, we need a place to grow to. Which is why the last key to a fulfilling life is having dreams.
Every person needs dreams of a better life and a greater future.
Without these, there is no direction for our growth, and no drive to spur our talents. This does not mean that we must feel discontented with our lives, but merely that we have a vision of how things could be even better. With those dreams we will go on to live our lives to the full extent of our potential. These are the things that separate mere existence from living. By striving to provide for these three key needs in our life, we are not only able to live well, but in the end, when we look back at our life we will be able to do so without any regrets.