A picnic may well be a metaphor for life. The essentials for happiness are the right company, moderate if sanguine expectations and a reasonable standard of physical sustenance and comfort, the whole being bedeviled by the belief that there is always something better to be had if only one presses on.

Childhood is the one prison from which there's no escape, the one sentence from which there's no appeal. We all serve our time.

A letter is paradoxically the most revealing and the most deceptive of confessional revelations. We all have our inconsistencies, prejudices, irrationalities which, although strongly felt at the time, may be transitory. A letter captures the mood of the moment. The transitory becomes immutably fixed, part of the evidence for the prosecution or the defence.

Murder is the unique crime, the only one for which we can never make reparation to the victim.

I love the idea of bringing order out of disorder which is what the mystery is about. I like the way in which it affirms the sanity of human life and exorcises irrational guilts.

Open your mind to new experiences, particularly to the study of other ­people. Nothing that happens to a writer – however happy, however tragic – is ever wasted.

[My father and his friends] believed in equality for women without troubling to acquire the basic domestic skills which would have made that equality possible.