Generally, one man armies are actually two person armies: the genius and their spouse. As a typical case, Einstein relied heavily on his wife. He needed vast amounts of time for uninterrupted thought. Guess who took care of everything else while he was in his study? Running a household is a part-time job for two people or a full-time job for one. If the genius needs to devote his or her full attention to their work, that leaves a full time job at home for someone else to do.