“Soft” condensed-matter science (also known as colloid chemistry) has revealed the nearly zoological complexity of long-lived structures that can arise from the competing interactions working in concert with thermal fluctuations both near and far from equilibrium. “Hard” condensed-matter science has revealed the stark beauty of elementary excitations shimmering on a placid quantum Fermi sea. The study of strongly correlated electronic states of matter is forcing us to unify these often disparate branches of materials science. Explaining confusing phenomena occurring in high-temperature superconductors and related materials seems to require that long-lived electronic structures be generated largely on their own, but perhaps with a little help from lattice disorder.We will explain the fruitful analogy between such systems and classical colloidal systems such as mayonnaise. Ordered crystalline, striped, or checkerboard phases and striped glasses emerge as candidate forms of highly correlated matter that may explain many puzzling observations of electronic materials.