In 1926 the psychoanalyst Marion Milner started keeping a diary with a field scientist’s rigour, on one question: not what she was supposed to want, but what actually made her happy. Seven years later she published the findings under the pen name Joanna Field, titled in homage to Woolf. Her own warning in the preface is the best part — do not attempt this unless you are prepared to find yourself more of a fool than you thought.