Psychologically: A person is expected - in vain. Then he is searched desperately, one pursues all tracks, tries to reconstruct his way, besides, gets in empty houses, dead ends, labyrinths - the missing remain disappeared. (No fear, this dream announces the loss of a person not!) The missing person is a symbolic shape for a talent (art, sport etc.) which one would have developed with pleasure and would have realised. The dreamer has this - mostly not voluntary - renunciation never wound completely, so the subconsciousness processes the loss about the Abgängigkeitstraum: Forget it, it has taken care, does not load you any more with it!