The writer Wallace Stevens was appalled to find himself celebrating his 60th birthday. “A poet should be 30, not 60,” he wrote to a friend on receiving a congratulatory note. “It is incredible to me that I am 60.”

What then would the great American poet make of a rock band, a secret agent and a public relations company that are either celebrating their own 50th or 60th birthdays’, all showing no signs of slowing down?

Take the Rolling Stones first. A troublesome anti-establishment band of mainly south Londoners who played rhythm and blues, they are still rolling along 50 years later. Interviewed a year or so after they were formed, Mick Jagger was asked how much longer they would stay together.

“Maybe another year, possibly two,” replied Jagger in a surprisingly posh voice.

One may have died and another been replaced, but three of the original five are still together. They don’t even look that different, haven’t grown fat or bald or grey, just somewhat wrinkly. They were already looking outmoded in the middle of the 1970s when I first became interested in music. A new punk generation threatened to blow them away. So how did they react? Did Mick get a Mohican, Keith a nose ring and rip his jeans? Did Charlie Watts put a safety pin through his cheek?

No. Nor did they change very much. Other singers changed their hairstyles, such as Madonna, or their music, like Bob Dylan, while others, including David Bowie, did both. The Rolling Stones did neither, staying faithful to their sound and style, although they did start touring more.

The Rolling Stones’s longevity is matched by that of James Bond, the British secret agent with a licence to kill. The latest effort, Skyfall, is the fastest grossing yet, taking $87.8 million in the first weekend in the States alone. The film is a long, dark affair that hints at the decline of Britain and its influence in the world, and also at the lack of relevance of a secret agent in a world full of computers and cyber terrorism.

However, by the end of the story Bond is back and the baddies are blown up or lying on the floor with a knife in their back. Bond has been played by a succession of different actors over the years, probably the most popular being the first, Sean Connery and the latest, Daniel Craig, even if the latter looks more like a private in the infantry than a naval commander.

It seems that survival does not require constant change – Lenin’s mantra of constant revolution often ends up just destroying the revolutionaries – but that having a clear identity and a core message remain fundamental. And if you do something well, keep doing it.

The company is now renowned for its understanding of the digital market and social media, and less for its ability to cart twins around the countryside. It has learnt to adapt, even while it has retained its core values.

“The business in effect has morphed from pitching stories to traditional media, to working with bloggers, Twitter, Facebook and other social media, and then putting good content up on owned websites.”

Wallace Stevens, for all his objections that poets should be young, carried on writing verse into his 70s. At 75 he was awarded an honorary doctorate from Yale, “the greatest prize for a Harvard man”, and later in the year won a Pulitzer Prize. Bond fights on is bigger and busier than ever. And the Rolling Stones, they rock on too. As they sang and will doubtless sing again: “You can’t always get what you want, but if you try sometimes, you find, you get what you need”.