We age. It is the course of life we all travel regardless of our agreement with it.
Our awareness of self and the body, becomes a series of events that we exaggerate and delete. From the moment of birth to the last breath of death, each is recorded by the mind and the Essence. The process spanning the duration of an individuals existence are the stages referred to in the Michael Teaching as the Internal Monads.
Like the image above implies, growing up and then growing old, may preclude the development of actual maturity. Only grasping the subtitles and the conclusions that each state promises may guarantee a successful refinement of the personality and the furtherance of their personalities growth and development. Putting it another way, just because someone is a grown-up physically, does not make them an adult emotionally.