Ecologists once used "resilience" to mean simply how fast a disturbed ecosystem returned to its original state — a fast-recovering forest was resilient, a slow one was not. But long-term studies of coral reefs complicated the term. Some reefs bounced back quickly from a bleaching event only to bleach again within a few years, locked in a cycle of shallow, repeated recovery that never restored the reef's original diversity. Other reefs recovered more slowly but, once restored, persisted for decades without further collapse. Ecologists now increasingly reserve "resilience" for this second, durable pattern, treating speed of recovery as a separate and sometimes misleading measure.