Alex Lewis' entire childhood disappeared from his memory all because of a few critical moments in 1982.

He was riding his motorcycle home from a friend's wedding in West Sussex, England when he lost control of the bike and crashed.

Alex's helmet came off in the crash and he suffered a traumatic brain injury that left him in a coma for three weeks.

When Alex awoke from his three week coma, he discovered he couldn't remember anything about who he was or what he'd done for the previous 18 years. His whole childhood and sense of self were just gone.

He did, however, remember his identical twin Marcus, who was at his bedside when he came to.

Marcus recalled the emotional time in an interview with People.

"He actually said, 'Hello, Marcie,' our nickname for each other. Then the doctors started questioning him — 'Do you know what day it is? Do you know your name?' — and he didn't know anything at all."

Marcus stayed right beside Alex as he relearned everything, including how to do basic tasks like walk and brush his teeth.

As he got better, Alex's questions became more complicated, and Marcus helped him fill in his memories of the past.

Marcus told Alex stories about their great childhood with loving parents, including anecdotes about fun family vacations and other activities.

Unfortunately, these stories were about as far from the truth as it is possible to get. The twins had, in reality, grown up in a neglectful and abusive home environment where both their mother and stepfather were horrible to them.

Over 10 years later, Alex eventually learned the truth.

He felt betrayed by the one person he trusted most in the world: his twin.

"My brother had deceived me. All of a sudden I just couldn't believe anything anymore."

The twins are sharing their story in a Netflix documentary titled Tell Me Who I Am.

The special is named after the pair's memoir—Tell Me Who I Am: Sometimes it's Safer Not to Know—from 2013, available here.

The events that led to Alex learning the truth were the deaths of their parents.

Jack Dudley, their stepfather, died of cancer in 1990 and was followed less than 5 years later by their mother, Jill Dudley.

Alex realized something was up when his brother showed no signs of grief at their parents' deaths.

"His reaction was so different than mine."

Alex's therapist suggested that some of her observations about his family made it seem like abuse, but Alex was loathe to believe her.

"I was horrified, I said, 'How dare you say that?'"

There was one object, discovered while going through their mother's old things after her death, that brought everything to light: a photo of the pair as young boys, naked.

"I asked Marcus if we were abused by Mummy, and he just nodded yes. And that is a moment that he and I will never forget. From then on everything changed."

The pair didn't speak about it again during the following 20 years.

Marcus told People:

"It's not that I wouldn't tell him, I couldn't. I wasn't capable of telling him. It was too dramatic for me."

In 2013 Alex shared his story with a London newspaper and was offered a book deal to tell his story in more detail. This led the pair to be more open with each other about their childhood while writing the book, and eventually led to the Netflix special based on that book.

The experience turned out to be exactly the catharsis the pair needed to deal with their past trauma.

"What he really needed from me, which I never fully understood, was to tell him directly from my heart how I felt about it because it stopped him from making monsters in his head."

Alex gained a greater understanding of just what Marcus went through to try to protect him from their past.

"I didn't realize the enormity of what Marcus had done. He had to carry all of the pain — the fake story and his own story and everything else. So I was just in awe. We're closer than I can ever remember."

Marcus added that the pair are finally at a place where they have been able to truly move on with their lives.

"It took us a long time to get to this place, but now we've been able to move on and put the past behind us."

**If you think a child is suffering abuse in the U.S., call the Childhelp National Child Abuse Hotline at 1-800-4-A-Child or 1-800-422-4453, or go to www.childhelp.org.

All calls to the 24-hour hotline are toll-free and completely confidential. The hotline offers crisis intervention, information, and referrals to thousands of emergency, social service, and support resources.