Jung believed that old age is characterized by a "contraction" of one's forces. This is disappointing to hear from such a man. He must have depended too much on his intellectual powers alone, and lacked a practice of meditation to transcend the mind.
In growing "older" there need not be contraction, but the possibility of deeper expansion, unimpeded by the delusion that one's identity should be constantly confirmed by winning battles. Then there can be meteoric inward growth, even unto intergalactic spaces, because one gives up the need for external signs of affirmation.
Elderhood is an invitation to fully embrace your personal madness, now understood to be merely God, in the unique diamond singularity of the Self. Let your bold disarray be the secret harmony of the empty space between this world and the next. Be intimate with the Bardo.