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If you've ever seen the TV show Unforgettable, you've probably thought it would be pretty cool if you had a perfect memory. I mean, Detective Carrie Wells can remember everything, even the clues that everyone else forgot, and she can use that to solve crimes.

I mean most of people can't even remember what they had for a lunch yesterday. Your memory is probably a lot like that. Even though we remember the story of our lives and important life events, most of the boring going to school and going to work that happens every day gets lost.

But not for people with the actually-very-real condition called hyperthymesia, where they can almost perfectly remember everything that's ever happened to them. It's not the same as photographic memory, which is more about remembering everything you see, and as far as scientists can tell doesn't actually exist. Hyperthymesia does exist, though, and it can actually be kind of a burden for the people who have it.

We didn't even know the condition existed until 2006, partly because it's incredibly rare, with a few dozen confirmed cases at most, and also probably because people don't run to the doctor if their memory is too good. But the few people who do have hyperthymesia can remember basically everything they did, every day, starting from when they were about ten years old -- which is around the time when they start to realize their memory might be different from other people's. So if you're over 10 and you haven't noticed it yet, you probably don't have it.

Most people with the condition also have these memories very closely linked to calendar dates. Name any event they've experienced and they can tell you the day and date — or vice versa, telling you what they did on any date you pick from their lives. The first discovered case was a woman named Jill Price.

She wrote a letter to some neurologists asking for help, and hoped understanding her condition might help others. When the doctors followed up, they asked tons of questions about her memories of her life. Like, without warning they asked her to report every Easter she could remember since 1980.

Within 10 minutes, she wrote a list of every date that Easter fell on for over 20 years, plus memories from each of those dates, and only made one mistake. Now, some people with hyperthymesia have used it to their advantage. A man named Brad Williams used his skill to become a contestant on Jeopardy, and another used his memory to win vacations through trivia contests.

Another famous example is the actress Marilu Henner, who appeared on the TV show TAXI, then became an advisor for Unforgettable. Not everyone finds the condition easy to manage, though. Just imagine remembering every single time you've ever said anything you regretted in excruciating detail.

It's bad enough suddenly cringing because you remembered that time you sneezed all over your middle-school crush. Price, the subject of that first case study, reported that her memory was a burden. She said it was driving her crazy, running her entire life through her head every day, and she would keep diaries to try to stop thinking about the memories.

And in the 12 years since she first called attention to her amazing memory, scientists have discovered some clues about why this might be — although research is scarce since the condition is so rare. In 2012, a group of researchers found 11 people with the condition who were willing to participate in the study, and compared them to a control group on a variety of memory test, along with scans of their brains. Among other things, they found that the people with hyperthymesia scored higher on a measure of obsessive behaviors than the control group did.

Things like hoarding, needing organization in their environment, excessive collections, or avoiding germs. Their brain scans told a similar story. A few regions of the brain associated with autobiographical memory, like the temporal lobe, were either a different shape or showed more activity in the people with hyperthymesia.

But they also showed less grey matter concentration in places similar to what you see in people with obsessive compulsive disorder. The researchers were quick to point out that none of the people with hyperthymesia had been diagnosed with OCD, but it suggests that the two conditions might have a common mechanism in the brain. Plus, it seems like in some ways their memory is just as bad as the rest of us.

People with hyperthymesia did much better on a quiz about various dates — they could name the day of the week 97% of the time, they could name a verifiable event 87% of the time, and produce an autobiographical event 71% of the time. All of which was better than the control group, who were down near the single digits. But on most other memory tests, like for short-term and working memory, they did about as well as the control group — things like seeing how many meaningless digits they could memorize, or drawing an abstract design from memory.

And more recent research shows they're also about as susceptible to false memories as the general public. In a 2013 study, researchers compared twenty volunteers with hyperthymesia to a control group on a few tasks that typically produce false memories in a lot of people. One was a test that usually convinces people they saw a word on a list when it wasn't actually there, and another involved the suggestion that they saw a video of the plane that crashed into a field on 9/11, even though there's no video footage of it that we know of.

And overall, everyone did... about the same. The people with hyperthymesia even did a little worse with the false memory of the plane. Those results suggest that having hyperthymesia isn't like having a tape recorder in your brain.

You still need to reconstruct memories when you think about them, just like the rest of us — you're just really, really good at it for whatever reason. And you also probably know that even though the rest of the world tends to think hyperthymesia is the most amazing thing ever, being able to remember every single thing that's ever happened to you isn't all it's cracked up to be. Thanks for watching this episode of SciShow Psych!

When we started this channel almost two years ago, it was because our community on Patreon had grown to the point where we had enough support to make it happen. Our patrons voted for the new show to be about psychology, and since then, with your help, we've been able to dive into all kinds of research about our minds, and the thoughts and choices that make us who we are. If you're not yet a patron and you want to help us keep doing what we do, just check out patreon.com/scishow. [ ♪OUTRO ].