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Daniel Radcliffe - He may not have had siblings, but he grew up with Emma Watson and Rupert Grint anyway.

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Alicia Keys - As an only child, Keys' mother insisted she take piano lessons starting at age seven. She showed prodigious skill early on and her lifelong passion for music began. 

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Selena Gomez - When you name your first child after the one and only Selena, how do you follow that up?

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Leonardo DiCaprio - The lady's man is often asked about his own feelings about being a father, and he insists, "If it happens, it happens."

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Drew Barrymore - Who needs siblings when you have Steven Spielberg as a godfather?

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Al Pacino - Pacino's parents divorced when he was young, and his mother moved them to his grandparents' house where he was so bored that he found himself repeating the plots and voices of characters he had seen in the movies. One thing led to another...

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Brooke Shields - Shields began acting quite young, and at age 12 she controversially starred as a child prostitute in 'Pretty Baby.'

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Jack Nicholson - Nicholson was not only raised an only child, but he was also raised to believe that his grandmother was his mother and that his mother was his sister.  

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Elvis Presley - What many people don't know about the King is that he had a twin brother who was stillborn.

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John Lennon - Lennon was reportedly raised an only child by his mother's older sister, Mimi Smith.

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Betty White - This timeless star was the only child of homemaker Christine Tess and lighting company executive Horace Logan White.

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Lenny Kravitz - The musician himself only has one child as well. 

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Matthew Perry - Perry's parents divorced when he was one year old, and his mother subsequently raised him by herself in Canada. 

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Robert De Niro - As an only child, De Niro dropped out of high school to pursue his acting career. He apparently didn't want an only child himself, and he has six children.

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Samuel L. Jackson - Jackson's only-child upbringing may just be one of the reasons why he is the coolest man alive.

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Saoirse Ronan - The actress was born in the Bronx, New York, and is the only child of Irish immigrants.

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James Dean - Dean had a difficult upbringing as an only child, especially when his mother died when he was just nine. He was subsequently raised on a farm by his aunt and uncle in Indiana.

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Natalie Portman - Portman, the first person born in the 1980s to have won the Academy Award for Best Actress, was born in 1981, in Jerusalem.

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Gregory Peck - The late Hollywood hunk was an only child whose parents divorced when he was five years old.

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Frank Sinatra - Growing up as an only child on the streets of Hoboken may have contributed to the crooner's unwavering determination. 

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Sir Anthony Hopkins - Born on New Year's Eve in 1937, Hopkins was fittingly both a first and a last for his parents. 

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Annie Lennox - Born on December 25, 1954, Lennox was apparently the only gift her parents wanted. 

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Idris Elba - The actor was born an only child in London, England, to a father from Sierra Leone and a mother from Ghana. 

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Lea Michele - Though she didn't have siblings, Michele made good use of her friends when she was young, leading to her big break at just eight years old. She and a friend had gone to an open casting call for an up-and-coming musical, and mere weeks later, she was on Broadway.

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Robin Williams - The late, great actor once described himself as a quiet, shy child who only blossomed after joining his high school drama department. 

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Russell Brand - The comedian's parents divorced when he was only six months old, and he was subsequently raised by his mother, enduring quite a tumultuous childhood alone. But look at him now! 

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Sarah Michelle Gellar - Best-known for her role as Buffy the Vampire Slayer, Gellar had all the spotlight on her growing up without siblings. So much so, in fact, that she was discovered in a local restaurant, when she was just four years old.

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John Cleese - The actor was born an only child into a family of modest means, but his lack of siblings may have contributed to his ability to attend private schools and obtain a good education.

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Laura Dern - Dern was born an only child to two actors, and though she didn't have siblings, she did grow up around movie sets and industry professionals, landing several parts as a kid. 

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Shia LaBeouf - The actor had quite a difficult childhood, the ups and downs of which he faced without siblings, though he began acting when he was young.

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Elton John - Born Reginald Kenneth Dwight, this only child reportedly started to play the piano at the impressive age of four. At 11, he won a scholarship to the Royal Academy of Music. The rest is history.

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Charlize Theron - Not only was the actress an only child, but she was raised on a farm in the greater Johannesburg area, in South Africa.

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Pierce Brosnan - Brosnan's father left when he was just a child, and with no siblings it was just he and his mother.

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Adele - The singer's father left her and her mother when she was two years old, and she reportedly began singing at the age of four. Adele herself now has one child.

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Maria Sharapova - As an only child, the Russian tennis player must have had less distractions when practicing her swing.

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The Weeknd - The artist, Abel Makkonen Tesfaye, is an only child born in Toronto to Ethiopian immigrant parents. He was reportedly raised by his grandmother and mother after his parents separated.

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Adrien Brody -

Born an only child to a photographer mother, Brody would accompany her on assignments, and he reportedly credits her with making him feel comfortable in front of the camera.

See also: How to become a star in Hollywood

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