A coincidence occurs when two or more (apparently causally unrelated) events are connected in the mind of the observer. Such events are usually noticed when they seem odd, surprising or out of the ordinary. Coincidences typically concern simultaneous events but very improbable events are sometimes also considered as surprising coincidences if somewhat more distant in time. The term synchronicity is applied when a surprising concurrence of events is considered meaningful to the observer.
Common coincidence experiences include thinking of someone and then they call, turning on the radio and finding it is playing the song you are singing, or picking up the telephone to ring someone as they are about to ring you. More dramatic examples include finding a long-lost object in an improbable place or noting a dream that comes true. Inglis (1990) cites a case of someone getting up late after two alarms failed to go off, and catching a later train than usual as a consequence, only to find that the earlier one had crashed. Deschamps' famous example concerns plum pudding, which he came across just three times in his life. He was given his first taste as a schoolboy. Ten years later he saw some in a restaurant and was asked if he would mind sharing it with a Monseiur de Fontigibu. Years later he attended a dinner at which plum pudding was served, and amused himself with the thought that M. de Fontigibu would no doubt join them, and indeed as the pudding was served M. de Fontigibu was announced (Flammarion 1900).
Coincidence experiences are often taken to be personally meaningful and significant; Jung coined the term synchronicity for such events, though the idea that coincidences might have personal import is not new. Jung (1972) traced the concept of synchronicity to the Chinese concept of Tao (being in flow with life) and related it to the medieval doctrine of correspondentia found in the occult philosophies of Agrippa and Paracelsus (where all things are seen as in sympathy and interrelated).