Because many people limit themselves to just having a pleasant life, a life of enjoyment. Once they move beyond this, they might find a good life, or even a meaningful life where they focus on their virtues and strengths.
Eventually they might discover that what they really want is curiosity, open-mindedness, realistic expectations and the love of learning. They might also seek self control, mindfulness, gratitude and forgiveness. Can they have this? Yes, if they are patient and perseverant.
Above all, they learn that material things are not the main source of happiness.