Only 60 People in the World Have This Insanely Powerful Memory

Updated: Feb. 08, 2023

Highly Superior Autobiographical Memory is a rare condition in which people can remember nearly every day of their lives with precise detail. One woman explains how this works and how having HSAM has affected her life.

Markie Pasternak remembers exactly when she realized her brain was different. It was Tuesday, August 26, 2014, the beginning of her junior year at Marquette University. She sat in a class called Learning and Memory, a psychology course that covered how people learn and the different types of memory. (These are the five types of memory everyone has.)

The professor, Dr. Kristy Nielson, stood at the front of the classroom, going over the syllabus for the semester. She said if the class completed the required material, they would get into “the fun stuff.” That meant discussing people with abnormally impressive memories, who can play music completely by memory or map out an entire city after only seeing it once. They might even study a relatively new subject in the field of psychology: people who are able to remember every day of their lives.

Only-60-People-in-the-World-Have-This-Insanely-Powerful-MemoryCourtesy Lindsey Snow, illustration Tatiana Ayazo/

That’s me, Pasternak thought. I can do that.

Pasternak, now 23, is currently the youngest person with Highly Superior Autobiographical Memory (HSAM), a rare condition that only around 60 people in the world are known to have. Give her any date between 2005 and present day, and she will tell you what day of the week it was and everything she did that day in extraordinary detail. On December 11, 2006, her dad got distracted watching the Chicago Bears play Monday Night Football and accidentally cut off the top of their Christmas tree instead of the stump. On that day in 2009 (a Friday), she chaperoned a middle school dance and then went on a date with a guy she had started seeing two days earlier. But before that psychology class, she and those with knowledge of her ability only knew it as “the fun trick Markie can do.”

“I asked my high school psychology teacher (if she knew anything about my memory) … and she didn’t know,” Pasternak says. “She just thought it’d be cool if I went on David Letterman.”

Researchers at the University of California-Irvine reported the first known case of HSAM in 2006 and have been further studying it ever since. When a potential HSAMer is identified, researchers conduct a two-part test to confirm the diagnosis. First, they provide several dates (say, June 25, 2009) and participants must recall what major current event took place each day (that was a Thursday, and that’s when Michael Jackson died). If they pass that test, they move onto the second. A generator spits out 10 random dates, and participants must name the day of the week, verifiable events that occurred that day, and other descriptors like what the weather was like. These mnemonic devices will help you remember anything. 

Upon the recommendation of her professor, Pasternak took the tests over the phone on Monday, March 9, 2015. She got 9 out of 10, the average score for people with HSAM. The average score for those without HSAM is 2 out of 10.

People who have HSAM have different means of recalling dates. Pasternak describes her memory like a Candy Land board. In her mind, she sees each month as a different colored square; June is green, August is golden yellow, November is dark red. The months connect to form a path, weaving back to February 2005, when she had her first HSAM memory.

Once she finds the right month in the right year, she “zooms into” the square and visualizes each week as a 7-piece pie chart. To figure out the day of the week, she starts with a “go-to” date that she knows especially well. For instance, if you ask her about February 17, 2011, she’ll first recall February 14, 2011, a Monday.

Only-60-People-in-the-World-Have-This-Insanely-Powerful-MemoryCourtesy Lindsey Snow, illustration Tatiana Ayazo/

“I know that one because of Valentine’s Day,” she explains. “I know who I was with on that Valentine’s Day and what happened, and then I can kind of piece it together. Now I remember what happened on that Tuesday and Wednesday and Thursday.”

It takes time to recall those memories, but eventually, she can remember events down to the hour. “I can’t just memorize things,” she says. “That’s not how it works. I have to see it. I have to be there. I have to live it, or it doesn’t affect me.”

Hence, the specification of “autobiographical” memory. Those with HSAM aren’t able to recall current events that they didn’t personally hear about or experience. Pasternak knows Tom Petty died on October 2, 2017, but she associates his death with October 3, the day she found out and subsequently listened to “Among the Wildflowers” and “Freefalling” on repeat.

Pasternak participates in studies, online surveys, and phone interviews with the UC-Irvine research team a few times a year. In doing so, she learns more about the condition and meets others who have the same abilities. But perhaps most importantly, it gives her a purpose to what she long thought was a useless talent. Researchers believe people with HSAM have the extreme opposite of Alzheimer’s, and uncovering what is biologically different about HSAM brains could help treat Alzheimer’s, depression, and other mental health issues.

“It makes me so glad that I figured out I have [HSAM],” she says, “so I can help contribute to this growing body of research that has the potential to change lives.”

Here are some tips so you can improve your own memory.