For more than 30 years, Robin Williams was one of the funniest figures in show business.

The legendary comedian brought happiness and laughter to millions of fans around the world through his stand-up comedy routines, as well as through his starring roles in classic comedy films, including Mrs. Doubtfire and Patch Adams.

Tragically, Robin Williams passed away in 2014, a loss that fans believe is among the saddest celebrity deaths of all time. Robin Williams was a light of sunshine and joy in the world, and when he was gone, so was the light.

The actor would be 70 years old today, and fans continue to honor and remember him.

Since Williams’ passing, several details about his life have come to the surface. Sadly, while his on-screen appearances brought so much laughter, his real life featured a collection of sad moments in between the beautiful ones.

Here’s the tragic real-life story of Robin Williams.

Robin Williams Felt Lonely As A Child

Although Robin Williams brought joy to millions of people throughout his life, his own hardships began when he was still a child.

As Nicki Swift reports, he often experienced loneliness when he was a little boy—a fact that allowed him to relate to his Jumanji character Alan Parrish.

His father was an automotive executive and his mother was a fashion model, and both parents used to travel extensively, leaving Robin to be raised by nannies and staff.

Williams later opened up about how he finally connected with his parents. After seeing his dad laughing while watching The Tonight Show with Jonathan Winters, he understood that he could grow closer with his father if he could just manage to make him laugh.

During a 2001 interview on Inside the Actor’s Studio, Williams revealed that his father rented an old mansion, and in his loneliness, he had to learn how to keep himself entertained.

He also cites his mother as being part of his “whole comedy upbringing” as, from a young age, he was doing things to try and make her laugh.

Drugs Were Part Of Robin Williams’ Routine

Like many people working in show business, Robin Williams was introduced to drugs at the beginning of his comedy career and soon became addicted.

According to the 2018 biography Robin by Dave Itzkoff, by the time Williams had a starring role on Mork & Mindy between 1978 and 1982, doing cocaine was a regular part of the comedian’s everyday routine.

After comedian John Belushi died of a drug overdose in 1982, Williams reportedly gave up his cocaine habit.

It has been reported that he was actually present during the episode that took Belushi’s life, and was able to quit in time for his son Zak to be born.

n 1988, Williams explained his decision to stop his habit to People, saying, “His death scared a whole group of show business people. It caused a big exodus from drugs. And for me there was the baby coming. I knew I couldn’t be a father and live that sort of life.”

Robin Williams Struggled With Alcohol Addiction

During his early years in show business, Williams also became addicted to alcohol. Although he quit before his son Zak was born, he relapsed multiple times throughout his life.

Remarkably, the actor was able to stay sober for two decades, before relapsing in 2003 while filming in Alaska. Following this and family intervention, he went to a rehab facility for treatment.

Robin Williams Felt He Had Let Down His Children

Robin Williams was the father of three children: Zachary with his first wife, Valerie Velardi, and Zelda and Cody with his second wife, Marsha Garces.

According to Vanity Fair, the actor reportedly felt as though he had let his children down when his marriage to Marsha broke down and she filed for divorce in 2008.

His children told their father that he had no need to feel guilty, but according to his son Zak, he wouldn’t listen.

“He couldn’t hear it,” Zak recalled (via Vanity Fair). “He could never hear it. And he wasn’t able to accept it. He was firm in his conviction that he was letting us down. And that was sad because we all loved him so much and just wanted him to be happy.”

Robin Williams Was Diagnosed With Parkinson’s Disease

In May of 2014, Robin Williams was diagnosed with Parkinson’s Disease. He had been struggling with symptoms of the disease for a while, including a tremor in his hands, a slow gait, and a weakened voice.

The degenerative disorder attacks the body’s central nervous system and eventually severely impairs motor functions and cognition.

Vanity Fair posits that this was devastating for Williams, who had a fear of losing control over his own body after seeing his friend Christopher Reeve become paralyzed from the waist down following a broken neck.

As the months of 2014 went on, Williams’ symptoms began to worsen. He reportedly had trouble sleeping at night and was suffering from delusions.

Williams began seeing a therapist, exercised with a physical trainer, regularly rode his bike, and found a specialist to teach him self-hypnosis.

His Coroner’s Report Showed That He Had Lewy Body Dementia

Tragically, on August 11, 2014, Robin Williams died by suicide. According to ABC News, the coroner’s report from his autopsy showed that he had Lewy body dementia, a disease that affects the chemicals in the brain and can cause problems with a person’s mood, thinking, movement, and overall behavior.

Lewy body dementia can result in sufferers experiencing extremely graphic hallucinations.

Studies have shown that depression or depressive symptoms are common side effects of Alzheimer’s Disease and dementia with Lewy bodies.

ABC News theorizes that this progressive disease may have influenced Williams’ decision to take his own life.