Marcel Proust Quote

The bonds that unite another person to ourselves exist only in our mind. Memory as it grows fainter relaxes them, and notwithstanding the illusion by which we would fain be cheated and with which, out of love, friendship, politeness, deference, duty, we cheat other people, we exist alone. Man is the creature that cannot emerge from himself, that knows his fellows only in himself; when he asserts the contrary, he is lying.

In Search of Lost Time (1913-1927) - Vol. VI: The Sweet Cheat Gone (1925)