What HSAM is
Highly superior autobiographical memory, also called hyperthymesia, is a condition in which a person can recall an abnormally large number of their own life experiences in vivid detail. It was identified in 2006 by the American neurobiologists Elizabeth Parker, Larry Cahill and James McGaugh, working at the University of California, Irvine.
Those researchers defined it by two characteristics taken together: spending an excessive amount of time thinking about one's own past, and an extraordinary ability to recall specific events from it. The second without the first is a good memory. The combination is the condition.
The diagnosis
Pasternak was diagnosed in March 2015 and was, at that point, the youngest person known to be living with HSAM. Her continuous recall begins in February 2005, when she was ten.
That date is the kind of detail that distinguishes the condition from an unusually retentive memory. People with HSAM typically describe a starting point after which the days stop being forgotten, rather than a general improvement in recall. Everything before February 2005 is remembered the way anyone remembers childhood; everything after it is available.
The burden, and the gift
The Milwaukee Journal Sentinel's April 2016 profile framed the condition as a burden that becomes, in the end, a gift. The burden is well attested in the research literature: the recall is described as non-stop, uncontrollable and totally exhausting. People with HSAM report difficulty attending to the present and the future while continuously reliving the past, and particular difficulty letting go of traumatic memories.
What Pasternak herself said about it is contained in that profile, which could not be retrieved for this page. Nothing here should be read as a medical account of her own experience beyond the diagnosis and the starting date, both of which she has discussed publicly.
How rare it is
Fewer than a hundred people worldwide had been diagnosed with HSAM as of 2021, and only six cases had been confirmed in peer-reviewed articles as of April 2016. That makes it one of the rarest documented conditions of memory, and one of the few that is defined by an excess of function rather than a loss of it.
The named cases form a small and much-studied group: Jill Price, the first documented; Brad Williams, Rick Baron, Bob Petrella, H.K. Derryberry, Aurelien Hayman, the actor Marilu Henner, Nima Veiseh, Rebecca Sharrock, Joey DeGrandis, Tyler Hickenbottom and Emily Nash. Pasternak appeared on 60 Minutes Australia in August 2016 alongside Sharrock, an Australian with the same condition.
What is documented, and what is not
Firm: the March 2015 diagnosis; her status at that time as the youngest person living with HSAM; her birth year, 1994; her home town, Green Bay, Wisconsin; and the start of her continuous recall in February 2005.
Not documented in the material used here: her exact date of birth, who tested her, what her university studies were, what she does now, and her own description of daily life with the condition. The Journal Sentinel profile, which contains most of that, could not be retrieved for this page, and the general description of HSAM above is drawn from the research summary rather than from her. Nothing here follows her past 2016.
| Person | Country | Milestone | Age / Stat |
|---|---|---|---|
| Markie Pasternak | United States | She remembers every day of her life since February 2005, and cannot stop | Age 11 |
| Rebecca Sharrock | Australia | Highly superior autobiographical memory (HSAM) | — |
| Marc Umile | United States | Reciting 15,314 digits of pi | — |
| Krishan Chahal | India | Reciting 43,000 digits of pi | — |
| Rick de Jong | Netherlands | Reciting 22,612 digits of pi | — |
What is documented — and what is not
✓ Documented
- Diagnosed in March 2015 as the youngest person then living with HSAM
- Born in 1994, in Green Bay, Wisconsin
- Remembers every day of her life since February 2005
- Appeared on 60 Minutes Australia in August 2016 alongside Rebecca Sharrock
? Unverified, disputed or wrong
- Her exact date of birth is not published in these sources
- The Milwaukee Journal Sentinel profile could not be retrieved for this page, so her own account of the condition is not quoted here
- Who administered the diagnostic testing is not stated in this material
- Nothing documents her studies, work or whereabouts after 2016
Questions people ask about Markie Pasternak
How old is Markie Pasternak?
She was born in 1994, according to the research summary used here. No exact date of birth appears in these sources.
What is HSAM?
Highly superior autobiographical memory, also called hyperthymesia: a condition in which a person recalls an abnormally large number of their own life experiences in vivid detail, defined by both excessive time spent thinking about the past and extraordinary recall of specific events.
What does Markie Pasternak remember?
Every day of her life since February 2005.
How rare is the condition?
Fewer than 100 people worldwide had been diagnosed as of 2021, and only six cases had been confirmed in peer-reviewed articles as of April 2016.
Who discovered HSAM?
The neurobiologists Elizabeth Parker, Larry Cahill and James McGaugh identified it in 2006 at the University of California, Irvine.
Is HSAM a good thing to have?
The research describes the recall as non-stop, uncontrollable and exhausting, with difficulty attending to the present and letting go of traumatic memories. The Milwaukee Journal Sentinel framed it as a burden and ultimately a gift.
Where is Markie Pasternak now?
Not documented. The sources used here reach 2016 and go no further.
Quick quiz: how well do you know Markie’s story?
From what month does Markie Pasternak's continuous recall begin?
How many people worldwide had been diagnosed with HSAM as of 2021?
Which university identified and named the condition?
Sources
- Rare detailed personal memory a burden, and ultimately a gift — Milwaukee Journal Sentinel (archived), 2016-04-14
- Hyperthymesia — Wikipedia
Checked by the Geniuses.club editorial team. Ages are given as of September 2026.
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