‘Come on Nicky, you’ve got to come next door.” “I haven’t got to do anything,” says Nicky, in a response that is part humorous, part genuinely truculent. There, in a nutshell, you have Sir Nicholas Winton, reluctant hero, saviour of 669 mainly Jewish children from Czechoslovakia as Germany tightened its grip on the country in 1939, and someone who finds the restrictions of being 105 years of age after an energetic, challenging, implacable life more than a little frustrating.

The woman trying to shift him is Babs Armstrong, who has helped him to carry on living as independent a life as possible in the chalet-style house near Maidenhead he built for his young family in the 1950s. She wants him to move out of the sitting room and into the kitchen to have his photograph taken. Here, further battles ensue. “How many pictures do you want?” he asks of the photographer after a quarter of an hour and several hundred clicks of the camera. “Don’t you have enough by now?”

Winton is a bit deaf, tires easily, and his memory is not what it was. Interviewing him is tricky, but meeting him is thrilling, a touching-the-hem-of-history moment. His life encapsulates the 20th century. He was born in London in 1909 into a family of German-Jewish origin, highly cultured and well-connected; was educated at Stowe public school in the 1920s, and became a stockbroker. But he was a stockbroker of an unusual stripe, because he was an ardent socialist who became close to Labour party luminaries Aneurin Bevan, Jennie Lee and Tom Driberg.

In 1938, instead of going to Switzerland for the skiing holiday they had planned, Winton (whose family had just anglicised their name from Wertheim) and his close friend and fellow socialist Martin Blake went to Prague instead. Blake wanted to help the hundreds of thousands of refugees who had flooded into the city after Germany’s annexation of the Sudetenland. But in the end it was Winton who took the leading role, chivvying the Home Office into giving entry to eight trainloads of endangered Czech children over the next nine months. A ninth train was due to leave on 1 September, the day Germany invaded Poland and closed the Czech border. The 250 children who would have been on that train died in concentration camps.

In Prague, in October 2014, receiving an award for his actions. Photograph: isifa/Getty Images

It is a powerful story that remained untold for 50 years, until Winton’s late wife Grete gave an old scrapbook with photographs and the names of the escapees to Elisabeth Maxwell, a Holocaust researcher and wife of newspaper proprietor Robert Maxwell. The latter got wind of it and an article appeared in the Sunday People. That, in turn, led in February 1988 to an episode of That’s Life! in which, after thumbing through the old scrapbook, presenter Esther Rantzen suddenly revealed that Winton was in the audience and, sitting on either side of him, were two women who owed their lives to him. As children, they had fled Prague on the Winton trains, with their names on cards around their necks, heading for a new life with foster parents recruited by Winton’s mother in the UK. Cue shock – Winton, who was in his late 70s at the time, was given no warning of what was to unfold and was not best pleased to have been tricked for the purposes of instant television drama – and bucketfuls of tears.

It was the start of a curious coda to his life, in which he has been showered with tributes – a knighthood in 2003, a statue at Prague railway station, and, at the end of last month, Czechoslovakia’s highest honour, the Order of the White Lion. He even had a small planet named after him in 1998 by the two Czech astronomers who discovered it, and the map of the part of the solar system in which it is located is on the wall behind his favourite armchair.

He is grand, venerable, wise, universally lauded. But the truth is that though all the attention helps to pass the time, he doesn’t really want to be any of those things. “It gets a bit boring talking about the same thing for a hundred years,” he says when I ask him why he has to be chivvied into describing his role in the evacuation. He is keener for his colleagues in the enterprise, Doreen Warriner and Trevor Chadwick, who fended off the attentions of the Gestapo in Prague, to get the praise rather than him. “I wasn’t heroic because I was never in danger,” he likes to say of his own role, played out in London after his three-week trip to Czechoslovakia in late 1938. Winton has been dubbed the “British Schindler”, but he resists the analogy, suggesting Warriner and Chadwick, who stayed in Prague throughout the period leading up to the outbreak of war, are more obvious candidates for a Spielberg hommage.

Winton puts his lionisation down to longevity. “None of the others are here any more.” But surely he protests too much. He could have looked the other way, as most of Europe did, but he chose to act. “It turned out to be remarkable,” he admits, “but it didn’t seem remarkable when I did it. Some people are born great, some achieve greatness, and some have greatness thrust upon them.” He puts himself very much in the third category. “It’s only because I’ve lived so long that this has happened.”

Why did he do it? His daughter Barbara Winton puzzles over that question in her recent biography of her father, called If It’s Not Impossible ... Partly, he says, it was because of his family connections. “My family knew what was going on in Germany. We’d had people who were being persecuted staying with us. We had families staying with us. We had refugees staying with us. We were being fed the whole time with what was going on, which was much more than the politicians were.” But it was also because of his socialism. Through Blake he had become part of a leftwing circle that was opposed to appeasement, and by 1938 he understood the danger Czech Jews faced. Refugee groups were seeking to get endangered adults out, but no one was helping the children, and he took it upon himself to plug the gap.

It is often said he deliberately suppressed his role after the war, but that is not true. His daughter points out that when he stood (unsuccessfully) for Maidenhead council in 1954, he referred in his election leaflet to having “evacuated 600 refugee children from Czechoslovakia”. When necessary, he was open about what he had done. It was more that he didn’t want to suggest the evacuation was the key to his life, the moment that defined him, which is what all the coverage since 1988 has insisted upon. In many ways he saw what he did immediately after the war, when he worked for the International Refugee Organisation and then the International Bank for Reconstruction and Development (IBRD), as having a more profound impact.

Nicholas Winton in Prague in 1939. Photograph: National Archives

Another piece of apocrypha is that the story only came to light in the late 1980s because his wife unearthed the old scrapbook while she was cleaning out the loft. Family memories are hazy, but it seems they had talked about his role in the evacuation and did know about the scrapbook, though the reason why Grete took it upon herself to show it to Mrs Maxwell has been lost. I ask him whether he’s pleased she did. “I’m only pleased if it has some advantage to somebody,” he says. “Just to propagate the past is absolute nonsense. There was a famous Frenchman who says there’s only one thing we’ve ever learned from the past, and that is that we never learned anything from the past. [It was actually Hegel, but it’s a good line.] It’s all being done again, but rather worse. We’ve learned how to do the bad things better.”

Winton met and married the Danish-born Grete Gjelstrup while working for the IBRD in Paris in 1948. The marriage marks a watershed in his life. Before, he had been a cosmopolitan figure, fluent in English, German and French, travelling widely in Europe, and representing both England and France at fencing. Afterwards, he settled down in Maidenhead, worked in the finance departments of a number of companies (including Britain’s first iced lollipop maker), and brought up three children. Everything changed, but he loyally rejects my suggestion that it must have been dull after his wartime experiences. “It didn’t change from my point of view.” But the jobs he did surely weren’t worthy of him? What did he really want to do? “I don’t know. I just wanted to make some money, I suppose.” He had rejected City life because “the people had quite a different outlook on life to mine”, and now wanted to live simply, earn enough to get by – he insists he has never been wealthy – and raise his family. He should, I suggest, have become a Labour MP, alongside his hero Bevan in that postwar Labour government. He would have been an adornment. But his daughter Barbara says he never had any great ambition and lacked confidence. What he did have was anger at injustice and singlemindedness once he set out to right a wrong.

Winton’s youngest son, Robin, who was born in 1956, had Down’s Syndrome. Then, children with Down’s Syndrome were usually placed in homes, but the Wintons insisted he should stay with them. When Robin died suddenly of meningitis the day before his sixth birthday, Barbara recalls that little was said – she sees her father as a reticent man who embodies his own parents’ Victorian attitudes. But she believes Robin’s death affected him deeply, and Winton has remained active in the charity Mencap for the past 50 years. He got involved because of his son’s learning disability, and that, he says, has been the way his life has tended to run. “I respond very easily to outside events. One’s life is a matter of chance. Nothing that you’ve arranged for yourself works out.”

He has never been burdened, says Barbara, by an introspective nature. He just gets on with it and takes life as it comes – probably the secret of reaching 105. Religion has, though, always interested him, and I ask him whether he wonders what comes next, what’s beyond this life. “I don’t think anything comes next. I don’t think there is a next.” Does that bother him? “It’s no use bothering about something that you can’t affect.”

Winton has come to see religion as organised hypocrisy. “I know crowds of people who go to church and the synagogue who aren’t religious. What is needed is something in which they can all believe irrespective of religion, which in most cases, dare I say it, is a facade. We need something else, and that something is ethics. Goodness, kindness, love, honesty. If people behaved ethically, no problem.” He has bent the ear of his local MP, Theresa May, about this, and says that whenever she sees him she immediately says “Ethics!”.

He is pessimistic about the future, anxious about nuclear weapons and our spiralling capacity for destruction. He also doubts that the probing eye of round-the-clock TV news will ensure that the mass delusion and passivity of democracies in the 1930s never recurs. “It needs more than that. It needs a complete reconception of life. Too late for me. ‘Know then thyself, presume not God to scan / The proper study of Mankind is Man.’ Whether that works I don’t know. It’s hasn’t worked so far.”