What HSAM is
Highly superior autobiographical memory, usually shortened to HSAM, describes people who can recall personal events from across their lives with unusual precision, typically indexed by date. Given a day, they can say what happened to them on it. It is a research category rather than a diagnosis, and only a small number of people have been formally verified as having it.
It is also narrower than the popular idea of a photographic memory. HSAM is specifically autobiographical: it concerns the events of a person's own life, not an ability to memorise arbitrary material on sight. People with the condition generally do not describe themselves as better at learning facts than anyone else.
Learning that it had a name
DeGrandis found out what to call his memory from a television programme: a 2010 segment on 60 Minutes about people with the condition. Before that, an ability to place any date in his own life was simply a personal peculiarity with no label attached to it.
That is a common route into the research literature for people with HSAM. The condition produces no symptoms that would send anyone to a doctor, so it is generally identified when someone recognises themselves in a description of it, and then contacts the researchers.
The downside in the headline
Time's framing in December 2017 was not celebratory. Its headline described the downside of having an almost perfect memory, and the piece's interest lay in what constant, unbidden recall of one's own past actually does to a person.
The argument is intuitive once stated. Ordinary forgetting is not a defect but a filter: it dulls embarrassments, softens grief and lets the past recede. A memory that does not fade keeps old material permanently available at full strength. That is the cost the article set against the obvious party-trick appeal of total recall, and it is why the magazine treated the condition as a subject rather than a stunt.
Where Joey DeGrandis is now
At the time of the profile he was 33 and working in marketing in the United States. That is the most recent position documented in the source used here.
No source used for this page reports where he works now, whether he has continued to take part in memory research, or anything else about the years since 2017. His exact date of birth is not published either; the birth year given here is inferred from his stated age in December 2017.
Vingt questions, huit minutes au chronomètre et un centile mesuré face à tous ceux qui l’ont passé. Sans inscription.
Passer le test de QI →Why researchers want these cases
A verified HSAM case is scientifically valuable out of all proportion to its rarity. Most memory research works by studying failure — what people forget, and under what conditions — because that is what is abundant. A person whose autobiographical recall does not decay in the usual way is a natural experiment in the opposite direction.
The practical constraint is numbers. Verification requires testing a claimed ability against records, repeatedly and across decades of a life, which is slow work; and the people who come forward do so voluntarily, usually after recognising themselves in press coverage. That is precisely the chain that brought DeGrandis into the story: a television segment, a recognition, and eventually a magazine profile that will itself have prompted the next person to come forward.
| Personne | Pays | Étape | Âge / Donnée |
|---|---|---|---|
| H.K. Derryberry | États-Unis | Un cas documenté d'hyperthymésie, ou mémoire autobiographique hautement supérieure... | 0 an |
| Aurelien Hayman | Royaume-Uni | Le premier Britannique identifié avec une mémoire autobiographique hautement supérieure | 14 ans |
| Joey DeGrandis | États-Unis | Mémoire autobiographique hautement supérieure vérifiée (MAHS) | 26 ans |
| Rebecca Sharrock | Australie | Mémoire autobiographique hautement supérieure (MAHS) | — |
| Krishan Chahal | Inde | Récitation de 43 000 décimales de pi | — |
What is documented — and what is not
✓ Documented
- Verified as having highly superior autobiographical memory
- Profiled by Time on 8 December 2017, at 33, while working in marketing
- Learned the name of the condition from a 2010 television segment about it
? Unverified, disputed or wrong
- No exact date of birth published; the birth year here is inferred from his stated age
- No reporting found on his life, work or research participation after 2017
- The source used here does not detail which research group verified him
Questions people ask about Joey DeGrandis
What is HSAM?
Highly superior autobiographical memory: the rare, verified ability to recall the events of one's own life by date with extraordinary accuracy. Only a small number of people have been formally identified with it.
How old is Joey DeGrandis?
Time reported him as 33 in December 2017, which places his birth in about 1984. No exact date of birth is published in the source used here.
How did he discover he had it?
From a 2010 television segment about people with the condition, which gave him a name for something he had always been able to do.
What does he do for a living?
He was working in marketing at the time of the 2017 profile. No later employment is documented in the source used here.
Is a perfect memory a good thing?
Time's profile was built around the costs. Ordinary forgetting dulls embarrassment and grief; a memory that does not fade keeps old material permanently available.
Where is Joey DeGrandis now?
No source used here reports anything about him after December 2017.
Is Joey DeGrandis on Wikipedia?
He has no article of his own; searches for the subject redirect to Wikipedia's page on hyperthymesia, the older term for the condition.
Is HSAM the same as a photographic memory?
No. HSAM is specifically autobiographical — it concerns the events of a person's own life, not an ability to memorise arbitrary material on sight.
Quick quiz: how well do you know Joey’s story?
What does HSAM stand for?
How did Joey DeGrandis learn the condition had a name?
What was Time's angle in 2017?
Sources
- The Downside of Having an Almost Perfect Memory — Time, 2017-12-08
Checked by the Geniuses.club editorial team. Ages are given as of September 2026.
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