If a person loves only one other person and is indifferent to all others, his love is not love but a symbiotic attachment, or an enlarged egotism.
Egotism is the source and summary of all faults and miseries.
Egotism, n: Doing the New York Times crossword puzzle with a pen.
If egotism means a terrific interest in one's self, egotism is absolutely essential to efficient living.