The veteran explorer Sir Ranulph Fiennes is proof of that, after becoming the oldest Briton to summit Mount Everest, at the age of 65.
It also makes him the first man to have crossed both polar ice caps as well as climbing the highest mountain on Earth.
Even after a lifetime of exploration and endurance feats, it is an astonishing feat.
The man who has become known as the world's greatest living explorer also had to overcome heart problems - he had a heart attack near the summit on his first attempt on the peak in 2005.
Exhaustion forced him to turn back when he tried to climb it again last year.
But Fiennes, who has suffered severe frostbite on most of his limbs, is someone who just does not give up.
"Plod forever, but never believe you are going to get there." That is how he described his strategy for getting to the summit just before leaving base camp.
Sir Ranulph Fiennes made his name as a polar explorer
Over nearly 40 years of expeditions from the polar ice caps to the deserts, one of his defining characteristics has been his bull-headed determination - usually coupled with a dry, British self-deprecating humour.
Ran - as everyone knows him here - has been spending part of his time at base camp writing his 19th book - about which he will only reveal the title: "Mad Dogs and Englishmen"
Sir Ranulph Twisleton-Wykeham-Fiennes, 3rd baronet - to give him his full name - made his name as a polar explorer.
To end up back in this country without an expedition on the horizon is a deadly state of affairs
Naturally competitive and patriotic, he saw more exploration "firsts" to achieve in the Arctic and Antarctic than other parts of the world.
Among those records: making the first unaided crossing of the Antarctic continent in 1993.
He and expedition partner Dr Mike Stroud dragged 450-pound sledges with their supplies for 90 days across the ice, covering more than 1,300 miles before encroaching starvation forced them to stop.
Ten years earlier, he made the first ever journey round the world crossing through both the North and South poles, travelling for almost four years on sea and land.
During an attempt to reach the North Pole unaided in 2000, he lost most of the fingers on his left hand to frostbite. It was Fiennes himself who carried out the amputations - when he got home, using his vice and a fretsaw.
It was not the first time some questioned his sanity. But Fiennes enjoys his sometimes eccentric reputation. "It saved me money," was his response.
Other endurance feats include running seven marathons on seven continents in seven days in 2003, just months after recovering from his first heart attack.
It would have been "more stressful" and bad for his health if he did not do things like that, he said before setting off.
Fiennes was born in 1944 to a family which traces its roots back to the invading army of William Conqueror.
His army officer father died before his birth. Fiennes grew up in South Africa and was then sent to Eton. But an occasional nose for trouble ended his own military career prematurely.
Just months after being accepted into the SAS, he was thrown out after getting involved in a prank to disrupt a film crew in his local village.
He was given an assignment helping the British-allied Sultan of Oman's army fight insurgents, for which he was decorated for bravery.
Mount Everest is the world's highest mountain
Then came an offer to lead an army expedition along Canada's river Yukon, which set his future.
His late wife Ginny was the organiser, a role in which she continued - coming up with the ideas for many of his more celebrated achievements. And so it continued, with Fiennes gradually earning more from writing and talking about his exploits, as his fame grew.
He was devastated by Ginny's death in 2004 from cancer. Since then most of his fundraising efforts have been for the cancer charity Marie Curie. Through his expeditions, he has raised more than £10m for good causes.
When asked why he keeps putting himself through so much, he can seem uncomfortable. "To make a living," is a common answer, as if he does an average nine-to-five job.
But speaking to us before leaving for Nepal, he said he could not imagine life any other way - even now that he is a pensioner and has a three year-old daughter by his second wife Louise.
Challenging himself is a "kind of addiction" he admitted.
"To end up back in this country without an expedition on the horizon is a deadly state of affairs," he said.
"It's like having no cigarette packet if you are a smoker."
Even before he left for Nepal, he was already planning his next adventure.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.