1. A method of predicting a location of a missing object based on a plurality of past sightings of a plurality of objects including the missing object and a new sighting of the plurality of objects except for the missing object, comprising: for a respective given object in the plurality of objects, memorizing the plurality of past sightings based on respective distances of respective remaining objects from the respective given object; for a respective given object in the plurality of objects except for the missing object, predicting a distance of the missing object from the respective given object based on the past sightings that have been memorized and the new sighting, to obtain a plurality of candidate locations for the missing object; and processing the candidate locations to predict the location of the missing object.