I have always liked to imagine that I was conceived the night before my dad went to war, mid-October 1939. I know he came home in 1940. He was part of the British Expeditionary Force that retreated from northern France and he was on the last boat leaving Cherbourg just as the Germans were on the outskirts of the town.

I learned three years ago, thanks to an appearance on Who Do You Think You Are?, that he had returned severely shell-shocked. I don’t know what impact his return had on my mother, brother and my infant self but before too long he was back with his regiment, the King’s Own Yorkshire Light Infantry, and he was absent from my life until his big frame filled our doorway in September 1945.

My recollections of those five years are thin but my mother, I know, adored, protected and spoiled my brother, Trevor and me. My cot was beside her bed in our tiny house and an earliest memory is rolling out of it and straight into her bed because the mattresses were of the same height. When I was too big for my cot, I slept with her. I only remember feelings of warmth, safety and love.

All that changed in 1945. Now there was a frustrated, angry, discontented man exploding around our small space. But the three of us learned to adjust, though our world could never be that idyll again. However, that was not the only adjustment – there were plenty of others: shortages, rationing, nothing to spare.

Do we wish to stick with our allies, our neighbours and remain in Europe, or do we wish to leave?

However, I slowly came to understand that other families were in a far worse case than us. Friends, fathers, brothers, uncles who had not come home or who had returned as ex-POWs, one of them from a Japanese camp.

In my house the Labour victory in the first postwar election that brought Clem Attlee to No 10 produced cheers and clinking of beer glasses. We had won the war, and the feeling in my community was optimistic. Our own people were back in power, and our neighbours felt that the working man was now going to have to be reckoned with.

Royal Festival Hall. ‘In 1951 the Festival of Britain brought to the country a sense of a unity … I went to London for the first time to sing in the Festival Church at the end of Waterloo bridge.’ Photograph: Jane Bown

In 1951 the Festival of Britain brought to the country a sense of a unity, even outside the British Isles. With my church choir I went to London for the first time to sing in the Festival Church at the end of Waterloo bridge. With our eyes out on stalks we walked around that stupendous celebration of Britain now and Britain to come.

For the first time I became aware of my country as a place hoping to share its future with others all around the world. Yes, millions had died but the hope now was that never again could a war like that be repeated. The world had suffered, not just Europe, and it seemed a lesson had been finally learned. The cold war was still ahead but the United Nations had come into being, and global responsibility and collaboration was also the future.

And when the European Union came into existence and the UK became a member, it was for me a triumph of all those convictions that the future must be one of worldwide cooperation and unity, and here we were paving the way with the beginnings of collaboration across Europe and learning the lessons of our own history.

In a little over a month’s time, all that will be at the mercy of the ballot box. For those of us who identify as Labour, we need only look to the back of our party membership cards, which carry the line: “By the strength of our common endeavour we achieve more than we achieve alone.” Ultimately, this is the decision we face. Do we wish to stick with our allies, our neighbours and remain in Europe, or do we wish to leave?

It is the biggest political decision of our generation, and it is our children and our grandchildren who will live with the consequences. Though I am convinced that the stay vote will win the day, nevertheless the fact that so many fellow British citizens want to leave Europe is shocking. Standing alone was how we were in 1940.

Why campaign to put us back there? I do not understand this thirst for isolationism. The most potent arguments, politically, economically, socially, urge us to remain. Let this just be a passing insecurity, and let us once more embrace reality, philosophy, common sense and hope for our country.