My book, William Shakespeare – Dark Phoenix, had its beginning on a warm day on the Isle of Mull when I asked Marianne, my wife (d 1984) if she could recollect a line from Shakespeare of which I could only remember that it was about education and psychological projection. ‘It is the eye of childhood that fears the painted devil’ came her quick answer. The words had little to do with education, but they made up the phrase I was looking for.

It was then that I saw how useful it would be to be able to look up a quotation not by a word or a phrase, but by a feeling, or even a vague thought.   I have a notoriously slippery memory for words – for an actor, not the most useful of attributes.  On the other hand, I do have quite a good memory for emotions.

I began, not very seriously, to make my first list of quotations and their associated emotions jotted down in a cheap notebook.  With the arrival on the market of the BBC computer, my list making became serious.   Now, with powerful computing on line, my database contains some 15000 references – and these, in the main, from only three of Shakespeare’s plays.

I began to see patterns in Shakespeare’s life that I had thitherto missed and wrote these up in several essays which, in the time-honoured way, I put in a drawer to be looked at later

Several years went by before I realised that the essays held the material for a novel – not about the William Shakespeare of whom we know so very little, but about the affect of profound loss on a creative mind.