Marilu Henner

Sunday, Dec. 19, 2010. That was the day CBS aired a 60 Minutes report on Marilu Henner's rare condition — highly superior autobiographical memory (HSAM) — that gives her the ability to remember everything. Only six known people in the world have it, and after the special aired, "everything changed," Henner tells TVGuide.com.

Curiosity piqued, she's participating in more studies, she's writing a book, and the biggest change of all, she has a new gig: as a consultant on CBS' new show Unforgettable. Starring Poppy Montgomery as Carrie Wells, a New York City cop with HSAM (which was formerly called hyperthymesia), the drama is based on J. Robert Lennon's short story "The Rememberer." The pilot script had been shelved for a few years until Henner's 60 Minutes report came along.

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"They took it off the shelf and said, 'This is going to be a great show now that people know what this is and it's being explored,'" Henner says. "[CBS Entertainment President] Nina Tassler, who has known me for a long time, asked me to be part of it. I said, 'Oh yeah, I'd love to be a consultant.' The show shoots in New York and I live [in Los Angeles]. I get to go in and talk to the writers and give them some ideas, read all the scripts."

But most importantly, she gets to put her memory to use and fact-check.

"[They sent me a preview], so I go online and it says, 'Hyperthymesia! Six people in the world have this! These people remember everything!' Then you see someone say, 'Hey, Carrie, show them that thing you do. March 27, 1998.' And so I'm thinking, 'That was a Friday, I flew back from New York to Los Angeles,'" Henner says. "And she goes, 'It was a Tuesday.' And I go, 'No! No! It was a Friday!' I start texting Ed [Redlich, the show's creator]! ... They ended up changing it because they had to. I said, 'You have to establish right from the beginning that she's good at this. Not the first thing out of the box and she's losing it.' ... So I'm always catching things like that in the script. Or there was a reference to a piece of music. They said it came out in 1983 and I said, 'No, it came out in 1985.'"

Watch the 60 Minutes report on Marilu Henner

Henner has known since she was 6 that she has an unusual memory, but never thought much of it until a friend brought it up when she was 18 — or more specifically, on Sunday, May 24, 1970 — and she started paying attention to other people's memories. The former Taxi star remembers each day vividly and can tell you every detail of what she experienced. The constant stockpiling of information is not overwhelming for Henner and she never struggles to remember anything, but the same can't be said for the others with HSAM. Jill Price, who also has the ability and appeared on a Primetime special, was greatly overwhelmed by the skill, which came as a shock to Henner. "I think, in writing Carrie, they sort of took that aspect from [Price's] story, but it was never overwhelming for me. It's just the ultimate organization tool," Henner says. "It's just recorded and then it's there and then it's easy access. Although I've seen my brain scans and they're pretty freaky!"

Taking even more poetic license with the show, Redlich & Co. included a caveat with Carrie's memory: The only thing she doesn't remember is the night of her sister's murder. "Certainly I never had anything traumatic like that that was blocked out, but this is television, so we have to make it interesting," Henner, 59, says. "I have no idea [if the others with HSAM have blocked something out]. We didn't get into group therapy. But it's a major story point."

One thing she was adamant about was how to portray Carrie's flashbacks. People with HSAM see everything through their own eyes again. In other words, they're not watching themselves, à la Scrooge in A Christmas Carol. "But you can't have an actress with a camera on her forehead ... so they do it in a very interesting way," Henner says. "You know she's in her body in present time reliving it, being inside of herself. They show her, for example, kneeling over the body and she remembers, and you get the idea that she's back at the crime scene.

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Henner will guest-star on the show, most likely during November sweeps, as Carrie's aunt who has Alzheimer's. In the meantime, she continues to dole out personal stories for the show to incorporate, is finishing her book about memory and is tormenting her 15-year-old son, Joey, who she believes has HSAM too. He cannot be tested until he's 16 and it is unknown if HSAM is hereditary because no one else with it has children. "He's not owning it yet, but I know he has it," Henner says. "It's not that he doesn't admit it; he doesn't want to be challenged too much. I sometimes say the wrong date just for him to go, 'No, Mom, you're wrong. You were mad at me that day because of blah-blah-blah.' 'No, I don't remember being mad at you.' So we go back and forth."

Using a little white lie to mess with her son, however, is the only time Henner would ever lie. "I like accuracy. Not only do I want to be right, but I couldn't track a lie because so many things are connected," she says. "[HSAM] is totally a blessing! Oh my gosh! I've never even seen one downside to it. Nothing. Anyone with it won't want to lose it."

Unforgettable premieres Tuesday at 10/9c on CBS.