Invert Always Invert

Munger borrowed this phrase from the 19th-century German mathematician Carl Jacobi, whose maxim "man muss immer umkehren" (always invert) guided his approach to problem-solving. Munger applied it throughout his career: rather than asking how to succeed, ask how to fail — then avoid those things. He used the principle in speeches, Berkshire annual meetings, and Poor Charlie's Almanack (2005), and considered it one of the most powerful thinking tools available.