Familiarity breeds contempt.

The proverb warns that repeated exposure can erode respect: what is once impressive, mysterious, or authoritative may come to seem ordinary, and ordinary things are easier to dismiss. It can apply to personal relationships (taking loved ones for granted), social hierarchies (overfamiliarity with leaders or institutions), or aesthetic experience (novelty wearing off). The saying is not an absolute law—familiarity can also deepen affection—but it captures a common human tendency to undervalue what is close at hand and to let intimacy slip into casual disregard.

Familiarity breeds contempt.
Familiarity breeds contempt; contempt breeds hatred.
Familiarity breeds contempt, while rarity wins admiration.