Olivia Newton-John came over from Australia and sang her way into our hearts with her first hit single, this Bob Dylan song, If Not For You.

I realise that for a generation of people just a bit younger than me Olivia Newton-John is synonymous with Sandy in Grease. But by the time that came out I was far too punk and far too cool (at least in my own mind) to be interested in that. I still haven’t seen it, although obviously there’s no escape from the ‘Tell me more, tell me more’ song (and the other one), so I feel like I’ve seen and heard the best bits anyway.

I also realise that for people a little bit older than me this song is synonymous with Bob Dylan, who wrote it. But in 1971, when Olivia Newton-John, a fresh-faced Aussie blonde, took it to No.7 in the UK charts, I had never heard of Dylan, let alone heard his New Morning album of the previous year. I still haven’t – the second vast gap in my cultural education.

Nor did I know this song had also been done by George Harrison, or that Bob and George had sung it together at the Concert for Bangladesh, which was apparently a Big Thing. Consequently, I had no idea that Olivia Newton-John had arranged her version after the Harrison one, with the nice slide guitar, rather than the strumming and harmonica of Dylan’s which, to my eternal shame, I had never heard until I gave it a listen just now.

It’s OK but I prefer George’s to Bob’s and (call me a heretic) I like Livvy’s best, because that’s the first version I heard. She lends it a lightness and innocence – and she wasn’t a beardy weirdo. Still isn’t, to the best of my knowledge.

Today she’s an activist for numerous good causes, including the environment and animal welfare, at the age of 71. I learn that her grandfather Max Born won the Nobel Prize for physicis and her father was an MI5 officer working on the Enigma project at Bletchley Park, who took Rudolf Hess into custody during World War II.

After the war he became a headmaster in Cambridge, before emigrating to Melbourne when she was six. Lovely Livvy (her first performing name) had already won a Hayley Mills lookalike contest when she triumphed in another teenage talent contest, earning the prize of a trip to Great Britain, where she was signed to Decca and became a star. She’s also a third cousin of Ben Elton.