Worry is a special form of fear. To create worry, humans elongate fear with anticipation and memory, expand it in imagination, and fuel it with emotion. The uniquely human mental process called worrying depends upon having a brain that can reason, remember, reflect, feel and imagine. (..) Worry is what humans do with simple fear once it reaches their cerebral cortex. They make it complex.

// Edward M. Hallowell, 1997, Worry , Controlling It and Using It Wisely