There's a reason we all dream about growing up to be celebrities as children - or at least I did.
It's easy to imagine that celebrities don't have a care in the world.
They're rich, famous, and surrounded by people who adore them.
But by now we know better: celebrities are just regular people, and some of them have lived heartbreaking lives before becoming famous.
These 15 stars have tragic life stories that even their fans don't know about:
1. Joaquin Phoenix
The Gladiator star and his famous brother, River, grew up with their parents in a religious cult called The Children of God.
River later revealed that he was sexually abused by other members of the cult, and the Phoenix children were forced to perform for change in the street to feed their family.
While the brothers found success in Hollywood, River battled a drug addiction that would eventually take his life.
Joaquin and his sister Rain actually watched their brother overdose in front of the Viper Room nightclub in 1993.
"After River's death, I felt like I was in an altered state. It took me over a year to get my life back," Joaquin admitted.
"Dealing with death is always difficult, but suffering in public adds a whole new dimension."
While Joaquin is slowly recovering from his painful childhood, he has publicly battled his own alcohol addiction.
2. Shania Twain
Before hits like "That Don't Impress Me Much" made her a country music legend, Twain grew up in poverty.
The singer recalls her family was so poor they would often struggle to pay for new shoes or lunches.
Twain and her mother were also regularly abused by her stepfather, Jerry.
"I would get physically involved sometimes with my parents' fights," Twin said.
"I just thought that he would kill her. One of these times"”he was gonna kill her."
Sadly, both of Twain's parents were killed in a car crash. Alone at age 22, she began performing to make ends meet.
Against all odds, Twain has managed to become one of the most successful musicians ever.
3. Demi Moore
Moore's mother Virginia was only 19 when she gave birth to the future movie star, and Moore's father abandoned them both.
While Virginia quickly remarried, her new husband was a violent alcoholic.
He terrorized Moore and her mother before committing suicide when the actress was just 17.
Moore began to put these family tragedies behind her as she began her acting career, but her mother struggled with her own demons.
The pair stopped speaking in 1990 after Virginia left a rehab center that Moore had paid for.
The pair only made up just before Virginia's death from cancer in 1998.
4. Keanu Reeves
Like a surprising number of celebrities, Reeves was abandoned by his father when he was just a toddler - and he saw him for the last time ever when he was only 13.
His globe-trotting mother remarried multiple times, and Reeves was expelled from his high school in Toronto.
While roles in movies like Bill & Ted's Excellent Adventure made him famous, Reeves lived through even more tragedy.
He fell in love with actress Jennifer Syme, and they were expecting a child together.
But Syme's baby was stillborn at eight months, and she died in a car crash less than two years later.
On top of everything else, Reeves' sister Kim has been battling leukemia for more than a decade.
"Grief changes shape, but it never ends," the actor said.
"People have a misconception that you can deal with it and say, 'It's gone, and I'm better.' They're wrong. When the people you love are gone, you're alone."
5. Marie Osmond
The singer, who came to fame after hosting Donny & Marie with her brother, has quietly suffered a number of family tragedies.
While they were all smiles on TV, both of the singing siblings battled depression - postpartum depression in Marie's case.
Donny and Marie's other siblings have also been struck by what some call the "Osmond curse."
One went bankrupt, one battled brain cancer, one has multiple sclerosis, and two were born deaf.
But the most heartbreaking chapter of Marie's life came in 2010, when her son Michael committed suicide at age 18.
6. Dylan McDermott
McDermott is famous for playing crime fighters on The Practice and Dark Blue, but the actor solved a real life cold case with a tragic connection to himself.
When McDermott was only five years old, his mother Diane died under mysterious circumstances.
Her boyfriend, John Sponza, said Diane had been cleaning a gun when it fired, killing her.
McDermott had been locked outside the house by Sponza at the time, and heard the fatal shot.
It took more than four decades, but McDermott finally convinced police to re-open his mother's cold case. Soon, they found evidence that Sponza had murdered Diane.
Sponza could not be put on trial - he had already been murdered years earlier - but the case brought closure for McDermott.
"I've come to the point in my life where I'm able to begin to process all of this," he told police.
7. Oprah Winfrey
Today, Winfrey is one of the world's richest women and TV legend.
But she was born to a teenage housemaid, and grew up being abused and mistreated by her family.
As a girl in rural Mississippi, Winfrey's grandmother would beat her with a stick over any misbehavior.
Her mother was so poor that she put one of her daughters up for adoption, and the TV host only learned she had a half-sister in 2010.
Winfrey has also revealed that she was sexually abused by two older relatives and a family friend as a child.
After running away from home at age 13, Winfrey had a child the next year. But the baby boy died shortly after his premature birth.
While her early life was incredibly difficult, Winfrey says it shaped her into the successful person she is today.
8. Kelsey Grammer
He made us laugh with his classic roles on Frasier and Cheers, but Kelsey Grammer's life story will bring you to tears.
Born on the U.S. Virgin Islands, Grammer's parents divorced when he was a toddler, and he was raised by his grandparents.
After they died, Grammer moved back in with his father. But then he was killed in a home invasion when Grammer was only 13.
The worst tragedy of all came in 1975, when Grammer's younger sister Karen was abducted and killed by a pair of notorious spree killers.
Grammer didn't even learn his sister's fate until a week after she went missing.
In spite of everything, Grammer is still hopeful about life - and has forgiven his sister's killer.
"Every one of us is going to experience some terrible loss," he said.
"I just got a big dose. For every story you hear that's tragic, there's another that's equally tragic or more so. I think you come to look at it as part of life."
9. Jennifer Hudson
The Dreamgirls star and former judge on The Voice rose to fame as a contestant on American Idol.
With a successful music and film career, it seemed like Hudson had everything a person could want.
But tragedy was waiting in the wings.
In 2008, Hudson's mother, brother, and nephew were killed in a shooting.
Police later charged the estranged husband of Hudson's sister-in-law with the crime.
The singer took a months-long hiatus from public appearances before returning for emotional performances at the Grammys and the Super Bowl.
But in recent years, Hudson's life has included even more sadness.
She separated from her ex-fiance, pro wrestler David Otunga, and the couple had a messy custody battle over their son, David Jr.
10. Roy Orbison
The legendary rock musician lived a short and troubled life.
Orbison and his wife, Claudette, were riding motorcycles together in 1966 when she crashed into the open door of a pickup truck, dying instantly.
Only two years later, Orbison was on tour in England when a fire broke out in his home.
Two of the musician's three children were killed in the blaze.
Orbison's older brother, Grady, also died in a car accident while traveling to visit him in 1973.
With all of the tragedy in his life, it's not surprising that Orbison was only 52 when he passed away from a heart attack.
11. Sofia Vergara
Playing Gloria on Modern Family has made Vergara the highest-paid actress on TV, but her life before stardom was anything but glamorous.
Born in Barranquilla, Colombia, Vergara gave up a career in dentistry to work as a model and actress.
But the attention attracted by her career put her family in danger: Vergara's brother was killed during a 1998 kidnapping attempt.
Since then, her younger brother Julio has been deported to Colombia after battling a drug addiction in America.
"To see somebody dying over 10 years, little by little, that's the worst punishment," Vergara said.
"Now he's like another person."
Vergara is also a cancer survivor, who is still taking medication after having her thyroid removed and receiving radioiodine treatment.
12. Charlize Theron
Growing up in South Africa, Theron's life was shaped by family tragedy at a young age.
Her alcoholic father, Charles, threatened Theron and her mother, Gerda, with a shotgun in a drunken rage.
Theron's mother managed wrangle the gun away to shoot and kill Charles in self defense, while the young actress locked herself in her bedroom.
At first, Theron said she tried to keep the traumatic event a secret.
"I said my dad died in a car accident," she explained. "Who wants to tell that story? Nobody wants to tell that story"
But since then, Theron has opened up about the shooting many times, revealing how much it shaped her life.
"That was my entire childhood," she told the New York Times.
"My trauma was all of that. I survived that, and I'm proud of that."
13. Joe Biden
Despite being one of the single most recognizable people on the planet, the former vice president's tragic life story is mostly unknown.
Biden had just been elected a senator in 1972 when his wife, Neilia Hunter, and their one-year-old daughter Naomi died in a car accident.
His young sons, Beau and Hunter, survived the accident.
Sadly, Biden would outlive Beau, who died from brain cancer when he was only 46.
In an emotional interview with Oprah Winfrey, Biden shared his final moments together with his son.
"[Beau] looked at me and he said, "˜Dad, I'm not afraid. I'm okay,'" he said.
"Dad, look at me," Beau told his father.
"Stop looking sad...no matter what happens, I'm gonna be alright, Dad. You've got to look happy. You've got to look strong for the family."
14. Marlon Brando
The star of The Godfather found success on the big screen, but his private life was as dramatic as any movie.
Brando's mother, Dodie, was an alcoholic who had to be carried home from the local bars by his father.
As an adult, Brando searched for love but never found it, fathering eleven children from multiple different women.
But the greatest tragedy of the actor's life involved his children.
His son, Christian, was a drug addict who shot and killed the boyfriend of Brando's daughter, Cheyenne, in the actor's home.
Cheyenne attempted suicide twice during the trial that followed, and lost custody of her son Tuki, before finally managing to take her own life.
15. Don Knotts
Like so many other great comedians, Knotts's life was actually quite sad.
Born to a poor West Virginian couple, Knotts regularly missed meals as his parents struggled to provide for their three sons.
To make matters worse, his father was a schizophrenic and an alcoholic, who sometimes held a knife to his son's throat.
Knotts was so terrified by these episodes that he repressed them completely. He only remembered them again as an adult in therapy.
While things improved after Knotts joined the army and went into show business, he secretly struggled with his own mental illness.
Knotts had hypochondria so severe it would keep him in bed for days.
When a doctor prescribed the actor anti-anxiety pills, Knotts became addicted to the medication.
There are many other Celebrities Who Tragically Lost Children.
And behind the scenes, even Lucy and Ricky were very unhappy.