When humans grow, they must shed some aspect of their former selves. This demands a painful renunciation, a renunciation of a little bit of who I was last week, of the comfortable skin I am used to calling myself.
For example, if a person with a volatile temper aspires to be less angry, she must change her knee-jerk reaction to events that set her off. In the process of overcoming this negative trait, she must speak and act differently than she was used to doing her whole life. Such effort to break habitual patterns requires not only hard work, but also the desire to be different, to shed the familiar fiery persona.