Andrew Ridgeley from Wham! looks back on 40 years of “Last Christmas”.

As Andrew Ridgeley of Wham! The first time he heard George Michael give his heart out on “Last Christmas,” he knew the beloved holiday song was special.

The magical moment occurred when the holiday spirit washed over his late bandmates in his childhood bedroom in London.

“We were killing time at his mother and father’s house. It was a Sunday afternoon and football was on TV,” Ridgeley, 61, told The Post. “And George disappeared upstairs where he had a little Fostex four-track recording studio where he recorded four tracks on a cassette. And (he) came back about an hour later and said, ‘Andy, Andy, you have to come upstairs and listen to this!'”

What Ridgley heard “written on the spot” was the beginning of the “Last Christmas” journey to 40 years of festive sentiment.

“He had written the simple keyboard track, the simple drum track and part of the verse and chorus,” he recalled. “And it was an amazing moment… I knew it was a hit album. Since we already had a few, we could recognize them as soon as we heard them.”

In fact, “Last Christmas” – released four decades ago on December 3, 1984 – continued the streak that Wham! ran after iconic hits like “Wake Me Up Before You Go-Go” and “Careless Whisper.” The holiday classic continues to bring joy to the world every season – it’s currently No. 4 on the Billboard Hot 100 – and is now being celebrated with a new 40th anniversary EP and Netflix documentary, Wham!: Last Christmas Unwrapped.

“It’s become part of the fabric of Christmas,” Ridgeley said. “It’s a very clever lyric with a melody that’s really charming, very pretty and very light. And the two of them work excellently together.”

Michael set out with the “goal” of writing a song that would become the number one Christmas single in the UK in 1984.

“It should be the icing on the cake for 1984. That was the intended purpose,” Ridgeley said. “When we grew up in the ’70s, Christmas No. 1 was a really big deal.”

But he added: “It was a challenge for George as a songwriter to write within given parameters… And also to write (a Christmas song) with such originality – the story of a love betrayed.”

When it came time to record the song at Advision Studios in London, Michael was a one-man band, playing a synthesizer, drum machine and sleigh bells in addition to vocals.

“It sounded just like it did in his bedroom,” Ridgeley said. “The band wasn’t necessary. He was left to his own devices.”

The Andrew Morahan-directed video – featuring Michael, Ridgeley and their fellow revelers at a ski resort chalet in Saas-Fee, Switzerland – was filmed just weeks before the single’s release.

“It was mostly a group of friends that we were enjoying our time in England with, so it was only natural to take them along to film a video that was basically a house party,” Ridgeley said. “If you take a bunch of 21-year-olds and give them free accommodation, food and drink, there will be a real party.”

But after being released as a double A-side single with the Make It Big hit “Everything She Wants,” “Last Christmas” stalled at No. 2 in the UK and was replaced by Band Aid’s “You Know That Christmas.” is?” – an all-star charity single that also features Michael.

Thirty-six Christmases later, the synth-pop bop finally reached No. 1 in the UK on New Year’s Day 2021. And in 2023 he finally became Christmas number. 1. “Just 39 years later,” Ridgeley said, laughing.

“Last Christmas” inspired the 2019 film of the same name and countless covers from Taylor Swift to Ariana Grande. Ridgeley’s personal favorite? Gwen Stefani’s 2017 version.

“I like the arrangement and the production is great,” he said. “It has a Phil Spector-like sound and a beautiful string arrangement.”

Eight years after Michael’s death on Christmas 2016, the Christmas Chestnut recently reached a new peak at No. 3 on the Billboard Hot 100.

And for Ridgeley, “Last Christmas” has lost none of its shine even four decades later.

“It is a song that has an essential freshness and vitality,” he said. “So I’m not sick of it.”