Think of the best day of your life – a wedding day, a graduation, something like that.

It’s probably pretty easy to  recall what day it happened, and who was there, right? Well, now imagine you remember what you had for breakfast the day before.

And whether your favorite  sports team won the next day. And whether it rained on  July 20th the previous year. Sounds like a superpower, but  the real-life people who remember everything that happens to them would  call it more of a mixed blessing.

Still, studying these “super  rememberers” could help us understand why I don’t even know what I had  for lunch two days ago – and more. [♫ INTRO] Highly Superior Autobiographical Memory, or HSAM, is a condition where people have an extraordinary ability to remember personal past events. It’s very rare – fewer than a hundred people are known to have this memory difference globally, though there are probably  cases that go unreported. These people can recall dates and  times of events in their life, and what happened during those events, with astonishing detail and accuracy.

People with HSAM have been able  to tell researchers the dates and times of seemingly uneventful days  picked at random from their past, as well as seemingly mundane  details about that day, such as what they ate, or who they met. Like, ah, yes, October 14th, 2004. My friends and I hung out at Claire’s.

It was 2004, it’s a pretty  safe bet we were at Claire’s. This is different than having a  so-called “photographic memory,” where people can memorize  lots of specific details. The A in HSAM stands for autobiographical, which means it only applies to things that relate to that person’s specific experiences in life.

So, people with HSAM are no  better than anyone else at – say – cramming for exams, even though they may remember lots of facts about their own past. So, what is it that allows the  brains of people with HSAM to store and retrieve these memories  so well, and could we learn from them how to improve  our own ability to remember? To understand why people with  HSAM have such good recall, it’s helpful to look at how  we actually make memories.

Memories are complex things. A single memory is made up of a network of neurons connected by synapses. Synapses are little gaps between the neurons.

Signaling molecules called neurotransmitters can jump the gap to carry information across. Imagine a memory, then, like a  series of roads connected by bridges. The more times the bridges are used, the stronger the connections and network become.

But the less the bridges are  used, the weaker they become, and eventually, they can crumble  away, and the memory fades. Something we wouldn’t bother recalling, like what we had for dinner  on a normal, boring Saturday, will probably disappear quickly. You’re not maintaining the  bridges, so they fall apart.

But not so for people with HSAM.  What keeps their ‘bridges’ intact? This SciShow video is supported  by

JMP: a statistical analysis software that makes powerful  analytics quick and accessible. Like, imagine running five  experiments at once with the same time and effort that it usually takes to run just one. JMP gives you the analytical power  to basically make that happen. JMPs prediction profiler tool  disentangles the contributions of different variables in your dataset,  to move science more quickly, with fewer inputs and more insights.

They even have screening  designs to cope with noisy data and identify the most informative  data points in the bunch. Let’s be real. If you can’t figure out what your data  means, collecting it can feel futile.

JMP is founded on the principle that  every statistic can be visualized, and that’s how we figure out what data means. So they do everything they can to help you comb through your data so none of it goes to waste. JMP offers a 30-day free  trial for anyone, anywhere.

To see the benefits of visual  statistics for yourself, you can go to jmp.com/scishow. HSAM might be linked to differences  in brain structure and function. Neuroimaging has shown that people  with HSAM have slightly larger and more active regions  associated with memory processing.

They also exhibit increased  connectivity between these brain areas – although this could be a result of their constant and highly detailed remembering,  rather than a cause. But interestingly, people with HSAM perform about the same as anybody  else in standard memory tests that involve information  that isn’t personal history. Stuff like memorizing random  lists of words or numbers, or recalling stories others have told them.

So, the clue to their superior  memory might be in personalization. Some theories suggest that emotional experiences play a significant role in memory retention, since we recall emotionally  charged events way more vividly. And one study found people  with HSAM were more likely to imagine and daydream, and had  a tendency towards absorption– that is, paying close attention to  any activity they are engaged in.

People with HSAM also often report experiencing compulsive memory retrieval– meaning they revisit past experiences  without actively trying to. That may further strengthen the  memory networks in their brains. So the idea is this: people  with HSAM have a greater and more emotional experience  of even mundane activities, and that creates a rich initial memory.

They then revisit those memories repeatedly, embedding memory networks strongly over time. And like I hinted before, HSAM isn’t exactly the fun superpower it might seem to be. Imagine recalling every embarrassing, sad, or rage-inducing moment you ever experienced.

People with HSAM have reported feeling overwhelmed by their constant, and  sometimes intrusive, memories. Like, my brain already brings up the time I called my teacher “mom” in  fourth grade often enough. Imagine that happening constantly and vividly.

Now, it can be difficult to  make general assumptions about memory from studying such a small group of people. Still, scientists are hopeful that  learning more about this unique group could help us understand  cognitive decline in people with memory disorders, like Alzheimer’s disease. Comparing active brain regions  of people with HSAM and people with Alzheimer’s could help  us understand how the disease progressively 'deletes' memory,  and which parts of the brain might be especially vulnerable  to autobiographical memory loss.

So, while we might not need science  to tell us that our most special moments in life stay with us  forever, these super rememberers can give us a fascinating insight into  why, and how, that actually happens. [♫ OUTRO]