On the 30th of January 1933, I was a 14-year-old schoolboy living in Berlin's Schöneberg district. It was late afternoon and already dark outside; my classmates and I were sitting in our classroom, waiting to be called into the assembly hall for a theatre rehearsal. Suddenly, we heard the growing sound of a marching band moving towards the street outside the school. From our windows, we could see men in brown uniforms, marching in step to the music. At the front and the back of the march were police cars with search lights, carefully scanning the walls of the buildings opposite our school buildings for political opponents of the marchers. That afternoon was 80 years ago, but I remember it as if it was yesterday.

My brother, already a student at university, was politically active and leftishly inclined, so I had a vague idea of what all this meant. Earlier that day, the president of the German Reich, Paul von Hindenburg, had sworn in Adolf Hitler as chancellor and assigned him the task of assembling a rightwing coalition government consisting of the Nazis and the conservative DNVP. The conservatives had supported the Nazi party – who were lacking the majority to form their own own government – because they thought that Germany needed to form a bulwark against the Marxist threat from the east, and because they believed that they could keep Hitler and his cohorts under control. As we now all know, they were wrong.

But even though I knew that the events of that day were momentous, I couldn't have foreseen how dramatically they would change my own life and that of my family. Even though my grandparents had already ceased being practising Jews, we were classified as non-Aryans. My aunt, a teacher, was soon pensioned off from the civil service and had to move to a Jewish school; my father lost his job as a commercial representative in the bicycle business soon after.

After the introduction of the Nuremberg racial laws in 1935, I had to stop myself from smiling at "Aryan" girls in the street – not easy for a 16-year-old. My brother had a non-Jewish girlfriend to whom he was secretly engaged, and was therefore constantly at risk of being arrested by the Gestapo. One evening he went to see her and did not come home to sleep. As we shared a bedroom, I was unable to go to sleep until he returned in the early morning for fear that he had been arrested. That night has stayed in my memory as the longest night I have ever experienced.

My parents still believed that they could sit out their days in Germany if they laid low – the Reichskristallnacht of 1938 put an end to their hopes. If we had stayed, we would have ended up in a concentration camp. We stayed awake two full nights in fear of being rounded up. Eventually, we managed to escape Germany – my brother to the US, my parents to Portugal, my sister and I to England, where I was first interned as a "friendly enemy alien" but after the outbreak of war volunteered for the army. Initially being only allowed to join the Pioneer Corps, I eventually became one of the intelligence unit's "secret listeners" listening in on the conversations between German prisoners of war.

On the 80th anniversary of Hitler coming to power, can we still draw lessons from that episode in history? Or has it been over-analysed to the point of exhaustion? My relationship with Germany these days is relatively unemotional – I have felt 100% British since I stepped on the boat at Hamburg. The Nazis cut my emotional ties with my country of birth. Berlin doesn't feel like my hometown, just a place where I happened to grow up.

But I no longer believe that totalitarian tendencies are a uniquely German problem, as people did at the time: genocides have happened since, and all over the world. The events of 30th January 1933 to me still serve as a warning of how quickly a conservative government can lose control of the situation when it starts to engage with political party further to their right – and there's a lesson in that for British politicians too. Eighty years are a long time, but the events of that day are still relevant now: if we forget what happened, it may happen again.