Growing up in North Korea, I thought we were the greatest people in the world, led by our Dear Leader. Because North Korea was so totally cut off, we didn’t hear anything of the outside world. We had only one TV channel, which showed only propaganda, and we believed everything.

In 1995 there was a terrible famine. I saw people dying on the streets in front of me. Their dead bodies would just be left under bridges or at railway stations. The smell of decomposing bodies was everywhere. I was very sad, but we didn’t know our suffering was because of the government. I thought all the world was suffering as we did.

I lived in Hyesan, very near the border with China. I was lucky as that’s how I found out the truth. We could pick up Chinese TV channels but were too far away for the authorities to detect. When we had power, I would lock myself in my room, use thick blankets to prevent light escaping, and watch Chinese TV. Everything I saw was so colourful, developed, commercial and totally different to what we had been told. But I didn’t know if what I was seeing was real or not. I thought maybe this was propaganda too.

In my village we had a good relationship with the border guards, they were like uncles. They helped me escape in 1997 and I went to live with my relatives in China, a 10-hour drive from the border. I was very naive, I was 17 and didn’t have a definition of “escape”. I just wanted to know the truth. I studied hard to learn Chinese, everyday for three years. I learnt for survival – that’s very motivating. When I was caught and interrogated by the police, I convinced them I was Chinese.

Later I got a real Chinese ID card by buying the identity of a mentally disabled woman. But whenever I saw a police car I was scared. I was traumatised. Most defectors have no idea where to go and are often sold as sex slaves into China. For years my Chinese family supported me, but they wanted me to have an arranged marriage so I ran away and worked as a waitress. It was a tiny salary but I was so happy, it was the first time I’d accomplished something. Finally I escaped to South Korea, and later helped my immediate family escape too.

My favourite place in South Korea is Jeju island, it’s a tropical paradise with sandy beaches, turquoise waters, and the magnificent Geomunoreum lava tube system of underground caves.

I love hiking to Mt Halla and Seongsan Ilchulbong peak, which has 99 sharp rocks surrounding a crater at the top, making it look like a gigantic crown.

The tradition of the haenyeo – “Korean mermaids” is unique to Jeju. These Jeju women dive into the ocean to gather shellfish and seaweed in a basket, without using any diving equipment.

My favourite Korean food is delicious black five-layered pork belly, cooked over a charcoal grill. And Jeju chocolate, in citrus fruits and green tea flavour, which is famous throughout Korea.

I’m very happy in South Korea, I have freedom, I can travel. But I paid a huge price. I lost my hometown, some of my family, my friends. When millions of people are in living in a prison in North Korea I often stop myself and think “Oh my gosh, how can I be happy right now?”. It’s my dream to go back one day; that’s also the dream of my mum. Every day she cries because she misses her siblings.

• The Girl with Seven Names by Hyeonseo Lee is published by William Collins (hardback £16.99). To buy a copy for £13.59 including UK p&p visit Guardian Bookshop. Hyeonseo Lee appears at the Edinburgh festival on Sunday, 30 August

Hyeonseo Lee’s full story in her own words