Maslow's hierarchy of needs
We cannot be truly happy without becoming everything that we want to become. People have different things that they might want in their life that go along with this level. These needs do not show themselves until all of the needs in previous levels have been taken care of. For example, if a person is worrying about feeding themselves and needs to think about their physiological needs, then they will not be thinking about self-actualization and their life goals. Making sure they have food and a home is more important. Someone only reaches the self-actualization level once all the other levels are fulfilled.