Why did I choose this partner? Was it his beauty? A striking character trait? Or was I guided by more sober considerations, such as fear of missing out or a very pragmatic desire for children? Was our motto in searching "Birds of a feather flock together" or "Opposites attract"? The mystery of partner selection often reveals itself, if at all, only after years and through psychological investigation. The riddle of collusion, the unconscious interplay of often shamefully hidden motives and aspirations, leads us into emotional depths, to childhood deficiencies, compensatory mechanisms, and attempts to heal our deeper personality. Mathias Jung, with the help of vivid case studies, cuts a path through the emotional thicket of partnership confusions and entanglements.