General relativity is the cornerstone of cosmology and astrophysics. It has also provided the conceptual basis for string theory and other attempts to unify all the forces of nature in terms of geometrical structures.
Sometimes a neighbor whom we have disliked a lifetime for his arrogance and conceit lets fall a single commonplace remark that shows us another side, another man, really; a man uncertain, and puzzled, and in the dark like ourselves.