I would not have missed this week’s production of Terence Rattigan’s The Winslow Boy at the Oxford Playhouse, even if I had not been there to review it. The play has a special place in my affections, partly for its own merits but chiefly because my first experience of giving a stage performance came when I played its title role.

Though it is 46 years ago, I still retain vivid memories of my debut as Ronnie Winslow, the 14-year-old cadet sacked from the Royal Naval College for allegedly stealing a five shilling postal order. Aged 11, I was three years younger than the character I was playing, an unusual circumstance for a school play, which is what this was. Normally, of course, kids play adults. My next role at Deacon’s School, Peterborough, for instance, was as Major Sergius Saranoff in Bernard Shaw’s Arms and the Man, who talked of things – “the higher love” among them – about which my 13-year-old self had no inkling.

The faded photograph of The Winslow Boy you can see above was given to me some years ago – oddly enough (though he didn’t take it) by the chap with the camera in it playing the press photographer. I can still ‘feel’ myself in that uniform, beneath that peaked naval hat, just as one can always remember how it was to sit in the driving seat of every car one has ever owned.

I remember vividly, too, the feel of the ghastly orange stage make-up with which in those days any aspiring young thespian’s face was always plastered. It took ages to wash off – and 11-year-old boys don’t like washing their faces.

Watching Hugh Wyld in ‘my role’ on Monday night, I was surprised at how many of the lines I remembered, especially those in the great interrogation scene with star barrister Sir Robert Morton (excellently played in the new production by Adrian Lukis) which is the high spot of the drama.

It builds to a tremendous climax with Sir Robert’s words “The boy is plainly innocent. I accept the brief”, on which a quick curtain falls to close Act I.

For some years afterwards, I entertained the mistaken belief that for a barrister to take on a defence case he needed to be personally convinced of his client’s innocence.

How innocent, in the other sense of the word, I was. It was not until I became a journalist, and regularly found myself covering court cases, that I discovered (very rapidly) that m’ learned friends are happy to defend any crook provided that he or she, doesn’t actually put their hand up to the felony.

My quizzing by Sir Robert also contained a line that I was often to hear in the courtrooms of Oxford and elsewhere over many years: “Would you tell me in your own words exactly what happened to you on that day?” Now whose words does a lawyer suppose a defendant might choose to use, if not his own? The matter puzzled me as a schoolboy, and still does.

Continuing a legal theme today,I was reminded by seeing The Winslow Boy of the occasion when I played a barrister on the stage of the New Theatre. This was almost exactly 30 years ago, in a touring production of Agatha Christie’s creaky old play Witness for the Prosecution. It was to be my last stage performance (to date, at any rate).

Partly with a view to writing a newspaper article (which I did), I agreed to take a walk-on (or rather sit-down) part as one of the legal team involved in the court proceedings at the centre of the drama.

No preparation for the part – merely a matter of rhubarbing and paper shuffling – was either necessary or, indeed, given. This had an unusual consequence in that I was, like members of the audience, entirely unaware of how the plot was to turn out. I followed its twists and turns with avid interest, and the denouement when it came was as much a surprise to me as to everyone else.

But this might have been the case even if I had seen it before. Was it not Ogden Nash who said that one Christie book was as good as a library, because no matter how often you read it, the ending will always come as a surprise?