Senex-Puer

From Wikipedia:

In Jung's theory, complexes may be related to traumatic experience, or not. There are many kinds of complex, but at the core of any complex is a universal pattern of experience, or archetype. Some of the key complexes Jung wrote about were the anima (a node of unconscious beliefs and feelings in a man's psyche relating to the opposite gender) and animus (the corresponding complex in a woman's psyche); and the shadow (Jung's term embracing any aspect of psyche which has been excluded from conscious awareness). Many Jungian complexes appear in complementary pairs: for example, the puer, or eternal youth, often appears in relationship to the senex, or archetypal old man. A puer complex might manifest as an individual's unconscious dread of growing up, of losing one's romantic ideals or freedom; a senex complex, by contrast, might be seen in a person who, without seeming to understand why, is driven to act out an "old man" role, in creative or destructive ways. Only when a complex results in destructive behavior would it be seen as pathological; otherwise, a Jungian view of psyche accepts the presence of diverse complexes in ordinary health.