Some days, he is part Egyptian or of Middle Eastern heritage. Other days, the reason he gives is that the nurse who registered his name made a typographical error.
These are the lighthearted lines Lincoln Forest Liqht Man (pronounced "Light Man") uses in response to the inevitable questions that come when people learn what his full name is.
The 18-year-old said: "Their eyes will light up, they'll be taken aback, and there'll be three questions: Are you local? What's your surname? Are you mixed?" The national gymnast, born to a Chinese Singaporean father and an Indonesian mother, is a Singapore citizen.
His name was chosen by his father, Mr Timothy Tan, as a reminder of their family's struggles while living in Pekanbaru, the capital of Riau province, in Indonesia.
Shortly after Lincoln was born in Bengkalis, Riau, the warehouse his family uses for business (such as exporting rice) was burned down by the natives. The business faltered, said Mr Tan, and they had to live temporarily in a forest in Pekanbaru with other Indonesians.
The 56-year-old added: "The forest was very dark and the people there respected me, so I wanted Lincoln to be the light to the forest."
The letter "q" in "Liqht", he explained, was inspired by the Chinese novella Ah Q, and serves as a reminder to his son not to look down on others.
Lincoln, a Singapore Sports School student, said he was initially sceptical when he heard the origins of his name.
"I was very young at the time and couldn't remember the whole situation surrounding my name and my family, but now I've come to embrace it - I think it's pretty cool and I'm proud of it," he said.
The Straits Times Young Athlete of the Year nominee does not mind the questions. He finds it easier to make friends because "they remember me as a person and they remember my name, and a lot of my friends thought it was a pretty cool name".
With a laugh, he added: "Throughout secondary school I used to mess with my friends by joking that I was Egyptian or Middle Eastern and they would believe me, and then I'd say, 'No lah, I'm Chinese'. That was quite fun."
He is also partly responsible for his 14-year-old brother's name: Russia Cityhall.
Mr Tan, an assistant nurse at St Luke's Hospital, said Lincoln had chosen the name "Russia" as he liked the country for its size.
He added: "When Russia was a baby, he cried especially loudly and since he had such a loud voice, I said maybe he should be a lawyer. In America, city hall is where the court is, so I named him Russia Cityhall."
Mr Tan's choices are not the only uncommon names among Singaporeans. Others include Abcde (pronounced Ab-si-dee) and Zyeaad (Zi-yad). In 2013, a man named Batman bin Suparman made headlines when he was jailed for theft, housebreaking and abusing heroin.
Little Ong, founder and creative director of design agency fFurious, told ST in 2014 that his name, coupled with his being the shortest in class, led to his being bullied as a child. He convinced his father to change his name via deed poll to Laurent Ong when he was eight.
Lincoln and Russia both said they would not change their names, although the latter admitted he is sometimes teased about it.
Lincoln said: "If I get into trouble, everyone will know I'm that guy. Thankfully, I haven't made too many mistakes."