"Perhaps the concept of the 'unlived life' calls for some expansion. It is not suggested that we should all obey every prompting of our desires, though it is healthy for us to give full attention to those desires which we will not fulfil, but which sometimes arise to plague us. We must be aware of the darker side of our natures. We must know what lurks in the shadows. Goethe said that he never heard of a crime which he could not imagine himself committing, under appropriate circumstances; that is the sort of self-knowledge we should seek. But the 'unlived life' is something different; it is the very often the life that has been put aside in order to serve the demands of a career, or an idea of one's place in the world, or simply--as in the case of the hero of Henry James's story--to serve one's own comfort and egotism. Very often it is love that is sacrificed in this way, but it may also be adventure, or a concern with the arts, or a friendship, or simply a greater freedom of action: these unlived elements revenge themselves , and sometimes they do it with compounded interest.
"We all know the saying that preacher's children are the worst harum-scarums, but do we ever look to see what ghosts of the parsonage they are laying by their rowdy behaviour? The banker's boy who becomes the school thief is bodying forth a repressed part of his father's concern for money. The young people who make a cult of promiscuous sex may be doing what their elders were afraid to do but longed to do. The druggies and the layabouts are living out the unlived life of too scrupulously moral and work-ridden families.
"This does not mean that these disreputable people are in the right, or that their elders are to blame for their bad behaviour. What is demonstrated is simply the principle of enantiodromia, which is the tendency of things to run into their opposites if they are exaggerated. Excessive self-love becomes no love at all; extreme prudence ends up by spoiling the ship for a ha'porth of tar; a rejection of all that is coarsely vital in life brings a shrivelling of sensibilities. As a very eminent psychiatrist once said to me: 'We attract what we fear.' What we fear is the portion of life that remains unlived. Our task, if we seek spiritual wholeness, is to be sure that what has been rejected is not, therefore, forgotten, and its possibility wiped out."
--from "Glooms and Gleams," in One Half Of Robertson Davies.