Before I became an orphan of the Holocaust my early family life was stable. I grew up as a German Jew in Frankfurt, and I was in a household with two loving parents and an adoring grandmother who spoiled me. My mother helped my father in their wholesale business and they went to synagogue every Friday. My father took me as I was an only child, despite the fact that usually in the orthodox tradition it's only boys who go. My father taught me to study, study, study hard and he sent me to a very good Jewish school even though it was not near the house. They took me there by bicycle until I was nine and half when I cycled myself. My mother was a very quiet woman and people say that she didn't get much of a chance to talk because my grandmother and I talked so much.
I was separated from my family in 1939, aged 10, and sent to a children's home in Switzerland that became an orphanage. I will never know how come my name was on the list for Switzerland because if I had been sent to Holland, Belgium or France I would be one of the statistics of one and half million Jewish children who perished. Instead I was in Switzerland with all of the uncertainties of not knowing where my parents were and what was happening. Still, up to 1941 I got letters from my parents and grandmother and the other grandparents. And then the letters stopped and I still did not know what had happened to them. We did not know about concentration camps until later in the war.
The start of the end of my happy family life began 74 years ago. The night of 9 November to 10 November 1938 became known as the night of the broken glass [kristallnacht] when the Nazis burned Jewish stores and attacked Jewish synagogues. A week later, they picked up my father for a work camp and that was the last time I saw him. That night everything changed. I remember my father was picked up by the Nazis wearing shiny black boots. There was no shouting or anything but I remember my grandmother giving the Nazis money, saying, "Take good care of my son." I was looking out of the window on the first floor and I saw my father boarding a covered truck and turning round and seeing me at the window and waving and smiling at me. He forced himself to smile and that was the last time I saw him. In January 1939 my mother and my grandmother came to the railway station to say goodbye to me when I was sent to Switzerland and I remember my grandmother running down the platform. I could see them until the train went round the corner and out of sight. That's the last time I ever saw them.
The children at the orphanage became my new family. When the letters stopped all I felt was uncertainty and what gave us strength was that all of us children in the orphanage were together, so we became like brothers and sisters. We gave each other support and wrote diaries. I do remember all of the songs of my childhood and they helped us to cope with being orphans. But the memories of my parents in my early childhood and the solid foundations of socialisation and strong values that they gave me never left me for one day. I was left with a feeling that because I was not killed by the Nazis – because I survived – I had an obligation to make a dent in the world. What I didn't know was that that dent would end up being me talking about sex from morning to night.
My introduction to sex was from a book called The Ideal Marriage by Theodor Hendrik van de Velde. My parents had hidden it in a bookcase and I knew where the key was. I was short – I'm only 4ft 7in now – so I climbed up and found the book, but at that point I didn't know that I was going to end up working in family planning or make 450 television programmes talking about sex. I knew that I wanted to be a psychologist.
After the war I was a sniper for the Haganah in Jerusalem before I got injured badly by a shell [during the Israeli war of independence]. I then ran a kindergarten in Paris while I studied psychology at the Sorbonne before emigrating to America and studying for a master's in sociology and the interdisciplinary study of the family at Colombia University Teacher's College. So you can see that my fascination with the importance of family was at the root of everything for me.
When Diane Sawyer came to interview me at my apartment for the programme 60 Minutes she asked my husband, Fred, who died 14 years ago, about our sex life. He answered, "The shoemaker's children have no shoes."
I have two children and four grandchildren and speaking to my children about sex was not difficult as by the time I was doing my doctorate they were already old enough to understand. I think it's vitally important to make sure that your children are sexually literate, but you should never pry. Make sure that your boys know about nocturnal emissions – wet dreams – and that girls and boys know about menstruation, but also know that children will not necessarily want to talk about sex with their parents. I would advise parents to bring a book home and leave it on the coffee table. If your children have questions make yourself available but don't pry. And if you have problems in your family, don't give up. Talk about things. Work things out and if you need to, go and see a therapist. And it doesn't have to be me.
• Dr Ruth's Guide for the Alzheimer's Caregiver is published by Linden, £10.59
