Considering all the problems I've been having with people at work, my partner is suggesting that maybe I need a filing system like the private filing system of the great composer Arnold Schönberg. After fleeing his native Austria after the Nazis came to power, he eventually ended up teaching music and composition at UCLA until his death in 1951. My partner A started teaching there as a young composer at the end of the 60s, and some of the older faculty remembered when they had been young grad students working as assitants to Schönberg, and of course they told stories about him.
Schönberg kept in his private office a little 3x5 card filing cabinet, with three drawers. These were filled with name and address cards for all the people he had to deal with. The drawers were labeled in German with three categories: Friends, Business, and "Schufte." Scoundrels. On many occasions his assitants observed him, after ending a phone call in heated tones, storm across to the cabinet, find a card in one drawer, move it to another drawer, and slam the drawer shut with great satisfaction.
After he died, they naturally examined the contents of these drawers with immense interest. Quite a few people were to be found listed in all three.