"Unforgettable" (Tues. at 10 p.m. on CBS) is about a retired detective (Poppy Montgomery) who has the very rare condition HSAM (highly superior autobiographical memory), which makes solving cases, if not a breeze, probably a lot easier for her than it would be for the rest of us. But as crazy as the driving concept of the show may seem (she remembers EVERYTHING? Always? Come on!), HSAM is not only real, a real star has the condition -- Marilu Henner, onetime star of the 70s series "Taxi" who is now a consultant on the show. I spoke with Henner briefly during TCAs and learned that, while HSAM seems more like a curse than a blessing on television dramas, in real life it's not so bad. Plus, you never lose your keys. 
 
If you hadn't heard of HSAM (or hyperthymesia) before "Unforgettable" or a "60 Minutes" episode that aired in 2010, don't worry -- you didn't miss it (or forget about it). A comprehensive study of the rare condition, which allows a person to remember every moment of their lives, was only published in 2006, even though Henner's been bragging about her memory on talk shows for years. "If you watch Bob Costas, I've been talking about it on that, Johnny Carson," she says. "I would go on shows and say I can remember every date and everything that's happened to me in my life and blah blah blah. People didn't know what it was. They didn't realize how incredible that is. It didn't have a stamp on it."
 
Since HSAM has been "stamped," though, there has been 20 documented cases (though as Henner points out "one [person] passed away, so [now] it's 19). But she says that, even though people have become more aware of HSAM, Hollywood has largely played fast and loose in portraying it. "There was an episode of 'House' that was, ugh, it was so bizarre," she says. "It was so inaccurate. It's always so tortured and crazy and oh, you can't go back there! And it's such a gift."
 
Henner does point out that she might have a slightly different experience with HSAM than others have had. "It's been tied to OCD (obsessive compulsive disorder). I've been tested for OCD and I don't have it, so I don't want people to think it's like OCD. I think three of the [first] six people [diagnosed] have OCD." And while Henner found acing tests a breeze while in school, "Not everyone is like that," she cautions. "A few of us were, some of us were not."
 
Still, Henner, who thinks one of her sons also has HSAM, was eager to accept a job as a consultant on "Unforgettable" to clarify what this condition is -- and isn't. "I really wanted to maintain the integrity of what this is. I didn't want it to get freaky and weird."
 
Talking to Henner, it's hard not to see the upside of HSAM -- she remembers every birthday, knows exactly where every pair of shoes she owns is (even if she hasn't worn them in years) and probably has the upper hand in a lot of arguments ("No, actually, you said THIS!"). But she's also putting her HSAM to good use -- she's allowing herself to be studied by researchers hoping HSAM holds clues in finding a cure for Alzheimer's disease. She's also working on a book, "Total Memory Makeover," which will give those of us who don't have HSAM tools to improve our memories. "I'm always like a teacher and giving information to people," she says. "I'm so into health, I'm so into the brain. I mean, acting is great and I'm glad I have a voice because of that, but I love all this other stuff, too."