For diarists as for other deviants, the fundamental question is the question of motive. Why? The natural supplementary is the question of audience. Who? To keep a diary is to posit a reader. Whether they recognise it or not, all diarists, especially dedicated diarists, hope to be read one day – read and understood – though not necessarily by anyone they already know or can identify. Some diarists, perhaps, write for themselves – their future selves – a wager on survival. Some may not know exactly what impels them. Some may be a little coy. ‘I sometimes wonder why I keep a diary at all,’ the Parliamentary socialite ‘Chips’ Channon recorded self-indulgently. ‘Is it to relieve my feelings? Console my old age? Or to dazzle my descendants?’ Several volumes later he could feel that ‘some day they may see the light of day and perhaps shock or divert posterity a little’.

Channon kept a diary almost continuously for nearly forty years. His companionable contemporary, Harold Nicolson, performed a similar feat. When the idea of publication was first mooted – a version edited by his son Nigel – the venerable Nicolson was asked the ‘why’ question by Nigel and his brother Ben. He replied, ‘Oh, because I thought I would.’