‘THERE’S Mary Poppins on telly,’ she said on Boxing Day, mellow after Christmas, a long walk and leftovers both solid and liquid. ‘Shall we watch it?’

I might have said, “No, I’ve seen it before, let’s try something new.”

But we watched it and enjoyed it hugely, as any but the grinchiest among us would. And it made me think about the value of going back to a well-known story.

Much was familiar: tidying the nursery while singing A Spoonful of Sugar; watching the old bird woman and singing Feed the Birds; riding a cartoon racehorse and singing Supercallifragilistic.

Over a gap of 50 years, more or less, it all came back fresh as new paint; I was word-perfect in many of the songs.

Some of the best-known extracts, no doubt, cropped up on Disney Time compilation programmes over the years but, even counting those in, a very long time had elapsed since the thought of the film even crossed my mind.

More interesting, though, were the things I didn’t remember. There were scenes and sequences I’d forgotten as completely as I recalled the others.

Take Bert, the chimney sweep, for instance (played by Dick van Dyke and, yes, his cockney accent is every bit as bad as legend has it).

In the film’s opening moments he’s earning a living as a one-man band, bass drum strapped to his back and cymbals on his knees; a little later he’s a pavement artist, drawing with chalk and holding his cap for pennies.

He’s not just a chimney sweep, he’s every kind of person scraping a living with little more than his wits for assets. I’d forgotten that, or never understood it in the first place.

Or Mrs Banks, the mother, so busy marching with the Suffragettes and campaigning for women’s right to vote that she has no time to look after her children.

Or Mary Poppins herself, dimpling at Bert and hinting that, super nanny though she may be, she has a personal life outside the nursery.

Or stuffy, pompous Mr Banks, the father, eaten up by his important job at the bank. It’s obvious to the adult watcher, if not to the child watching in the nineteen-sixties, that the man is lonely, strained and unfulfilled.

All these were things that I appreciated on Boxing Day, for the first time.

On reflection it’s fairly obvious that the parts of the film that stayed with me are those that appealed most to the boy I was when I first saw it, and the parts that went over my head then are the ones that hold more interest for the adult I am now.

But the whole is a vivid reminder that there is often much to gain from revisiting a book, or film, or any work of art that’s well made and has some depth: each visit reveals something new, something that was hidden the time before.