Amore affecting sight at the theatre could hardly be imagined. On to the stage at the end of the first night of To Sir With Love walked the man whose book inspired it (and the 1967 film starring Sidney Poitier). Aged an astonishing 101, sharp-suited Ricky Braithwaite had travelled from his home in New York to meet the cast and, in particular, the actor (Ansu Kabia) who was playing him as he had been 60 years before. Their embrace was a magical moment.

A dry eye in the house? Certainly not mine. By then, at the close of Ayub Khan Din’s sure-footed adaptation of Braithwaite’s memoir of school life, we had heard, heart-stoppingly, from the main ruffian at last tamed by the tyro teacher, one of the first black people in the profession here.

This was boxer, leader-of-the-pack Denham (Mykola Allen) whose surly indifference to matters educational had previously infected most of his fellow students in the leavers’ year at the ‘sink’ school in London’s East End.

That he had finally come under the benevolent influence of this inspiring teacher was proof indeed that Braithwaite’s methods had worked.

For those interested in theories of education the play makes for fascinating viewing. At its centre, and brilliantly portrayed by the ever-reliable Matthew Kelly, is the good-sort headmaster, Florian. His easy-going rule largely imitates the anything-goes approach famously pioneered by A.S. Neill at Summerhill, with pupils’ reports on staff and the like.

While this does not go down well with the traditionalist (and unpleasantly racist) maths teacher Weston (Paul Kemp) — “Stick it on the blackboard and if they don’t get it, tough” — two other members of staff largely toe the line.

They are domestic science teacher Clinty who, as portrayed by Nicola Reynolds, has more than a touch of Joyce Grenfell about her, and young Gillian (Peta Cornish) whose relationship with Braithwaite founders in the racial undercurrents of the time.

Braithwaite’s success as a teacher comes from the notions of mutual respect he instills in his charges. It’s a lesson still useful today.

The play, expertly directed by Mark Babych, comes to Oxford Playhouse from November 19-23.

I can’t wait to see it again.

To Sir With Love is on in Northampton until September 28.