Uuganaa Ramsay was raised in Mongolia but now lives in Scotland. She has recently been exploring why her ethnicity is linked to Down's syndrome, a condition diagnosed in her son.
"I don't like that word," says a woman sitting opposite me on the train, pointing at the title of the book I am holding. "Horrible word."
It's my memoir, but she doesn't know that. It was me who gave it the one-word title, Mongol.
I chose it because it has a deep meaning for me. It's the word I grew up using to describe who I am, reading it in poems, singing it in songs, writing stories with it and drawing pictures about it - it represents my identity and culture.
"Where are you originally from?' the lady asks. "Mongolia," I say. "Oh, of course. Of course you are," she says. I could see in her face that she had realised something that was now obvious but hadn't previously occurred to her.
The word Mongol is rarely used politely these days and is often unpleasantly shortened to "mong" but how on Earth did my ethnic identity end up becoming a slang word for stupid? Even worse, used by comedians to "push boundaries".
While working at the Royal Earlswood Asylum in the 1860s, John Langdon Down started to categorise the patients known then as "idiots", noting that one group all had a similar appearance. Mentioning a roundness of cheeks, the shape of eyes and other physical traits, he wrote: "A very large number of congenital idiots are typical Mongols."
Julie Coleman, Professor of English at Leicester University, thinks Down is saying "these people have regressed to an earlier state of humanity, which is the state of being Mongolian," noting also that this observation came some seven years after Darwin started to talk about evolution.
The name Mongol stuck even though some of Down's contemporaries doubted the racial theories he documented in the paper Observations on an Ethnic Classification of Idiots.
It wasn't until 1965 that the People's Republic of Mongolia complained to the World Health Organisation that the term was derogatory towards them, and it was replaced with Down's syndrome. The word was still commonly used in the UK in the 1980s.
But though my ethnicity is Mongol, the reason I get emotional is because we lost our three-month-old son, Billy, who was born in 2009 with the condition. Billy had a hole in the heart and died at three months old of a chest infection before being able to have surgery. The two meanings of Mongol collided for me then, causing pain, grief and anger.
When Billy was born it was suggested he may have Down's syndrome but before the tell tale extra chromosome was confirmed by a blood test, one doctor said that the original diagnosis may have been confused because of his ethnicity. So the link remains in people's minds.
For a BBC Radio 4 documentary, I returned to Mongolia after a gap of eight years. I love the country.
Mongolians have a nomadic tradition. I was raised in a yurt on the plains, have herded goat and sheep and journeyed by horse. We are good at adapting to different situations, have good survival skills and traditionally you can turn up at anyone's house and expect to be fed and get a bed.
John Langdon Down first stigmatised Mongols by linking them to the disability and 100 years later, after being widely acknowledged that the word Mongol shouldn't be used in the context of Down's syndrome, people frown on it or campaign against it because they know it's bad.
I started writing a list of countries where the term has been used in a derogatory way or to mean Down's Syndrome. I now have over 20 countries on my list.
I needed to speak up about it and I did by originally writing a book. Some people told me to be more resilient and follow what they did in their culture and just accept it. Some comforted me by saying languages change over time. But the question bugging me was who changes languages, because confusion over the term is still strong.
One half Mexican and half Mongolian person contacted me to say that in the Latino community, the words "Mongolito" and "Mongolita" still have very ugly meanings. "Introducing myself as a half Mongolian to my Hispanic acquaintances proved to be almost embarrassing throughout my teenage years," they said.
And another person from Morocco told me they have a son with Down's syndrome and that neighbours call her Mongolian and throw stones at them in the street. Again someone from South Africa wrote to tell me they were "shocked to find that Mongolians refer to themselves as Mongols when I arrived in Mongolia".
In the US, some Mongolian friends of mine were stopped on the street by a lady insisting they should take their child to a doctor because she suspected he had Down's syndrome. And while on a course in London, my Chinese and French classmates told me: "We didn't know someone from Mongolia could be normal and clever like you."
I want people to know you can use Mongol in the same way as you would refer to a Scot, Turk or Pole. It's fine. We can unlearn negative connotations because we learnt them. You can call me Mongol because I am one.
The Meaning of Mongol airs on BBC Radio 4 on 24 November at 20:00GMT.