Sound the trumpets! Let the angels sing! This, to paraphrase George Frideric Handel, is what Kiri Te Kanawa sang to a global audience of 600 million at the wedding of Diana Spencer to the Prince of Wales. It’s also pretty much what she said on the Today programme this morning. “There’s nothing more precious,” she said, “than hearing that glorious new-sounding bud” of a young voice “come to fruition as a flower”. When she teaches young singers, she said, and hears their “beautiful voices”, she doesn’t want to put her voice next to theirs. That, she said calmly, was why she would never sing again.

By coincidence, I’ve spent this week catching up on emails while listening to Dame Kiri sing Puccini and Verdi and Offenbach and Wagner and the Mozart opera – The Magic Flute – that first made her name. I don’t know how you describe a voice like that. Like the finest shiraz you’ve ever tasted? Like the richest, darkest chocolate mousse? Or perhaps, since we’re all now talking gender fluidity, like the voice of God?

It seems like a terrible loss to the world, but Kiri Te Kanawa is 73. The voice she built, through years of study and practice, has endured in a way so many people’s talents don’t. The average footballer, for example, has to retire at 35. So does the average dancer. Professional athletes generally last until around 33. And they’re the lucky ones. Gymnasts rarely make it beyond their early 20s. That’s also the time when most female models are dropped. According to some recent studies, adulthood now starts at 25. Some of these people, in other words, are retiring before they have even grown up.

We don’t usually think all that much about what happens when those people winning medals or matches, or plastered over magazines, are forced to leave that glory behind. Some of them are fine. David Beckham seems to have managed to keep the wolf from the door. And he looks pretty cheerful in his posts to his 40 million Instagram followers, unlike his (also very talented) wife. Some former athletes, dancers and models build new careers, or businesses, or lives. But quite a few do not.

When you’ve spent most of your waking hours focusing on one thing, and getting really good at that one thing, and being recognised and rewarded for doing that one thing, it isn’t at all easy to know how to cope when that one thing stops. It gives you an identity. It gives you a sense of purpose. Oh, and it pays the bills. Two out of every five professional footballers are declared bankrupt within five years of retirement. Many former athletes experience depression. Paul Gascoigne, Frank Bruno, Kelly Holmes and Andrew Flintoff have all talked about their struggles with mental health. And who wouldn’t feel that, after double gold, the only way is down?

Most of us don’t shine in the way these people have shone. We haven’t spent our teenage years getting up before dawn to plough up and down a pool or race around a track. We haven’t learned to fill a vast hall with a trembling vibrato voice. But most of us have learned how to do something. We do that thing in our jobs. We’re not stars, we’re not CEOs, but we do our jobs pretty well. And when we lose that job, it hurts.

Take it from someone who has lost a job: it really, really hurts. Employment in this country may be at near-record levels, but we are living through a revolution and some industries are being hit more than most. Journalists are being “disrupted”. Photographers and musicians are too. “Disruption” sounds great to the titans of Silicon Valley, but not quite so good to those who suddenly find themselves wondering how the hell to pay the rent. Ask the miners. Ask the shipbuilders. Ask the cabbies about self-driving cars. About a third of our jobs are at risk from the robots, according to a recent report from accountants PwC. That’s an awful lot of us who are going to have to learn how to do something else.

Last week John Motson announced his retirement as a football commentator after 50 years. A few weeks earlier, Henry Blofeld said he would retire from Test Match Special after 45 years behind the mic. Liam Neeson this week announced his retirement from action movies. His reason? “I’m sixty-fucking-five.” Lucky men. Clever men. They slogged, they shone and they knew when to go. Like Dame Kiri, they were the ones who got to make the choice.

Kiri Te Kanawa has been not just graceful, but canny. She started a new thing – teaching, mentoring and a foundation – while she was still doing the thing that gave her fame. And even when she was doing that thing, she thought she was never good enough. “I did keep trying,” she said. We must all keep trying. Sound the trumpets? Well, perhaps the bugle as we mark the end of some things and look to the new.

• Christina Patterson is a writer, broadcaster and columnist