Meet KCL, the 16-year-old with a memory sharper than 99.9% of people who can recall events from age 3 months

Most of us have fleeting memories. We remember only a few important things in our lives, often forgetting birthdays, anniversaries, names and even people. But for one teenager, it is different. Scientists have studied the teen, who has been given the alias KCL to protect his identity. According to the researchers, his memory is so strong that he can recall events from when he was just three months old. His memory is said to be sharper than that of 99.9 per cent of the population. Fewer than 100 people are believed to have highly superior autobiographical memory (HSAM), ScienceAlert reported.

Can recall memories via smell, song, or even a sentence

Cognitive researcher Krystian Barzykowski, whom KCL contacted in February 2025, said in a report that the teen had memories from early childhood (2010–2011) that were reportedly corroborated by his parents. He could recall detailed events from about half of the days that had passed since around August 2022, ScienceAlert reported. KCL's memories are said to be triggered by small cues, such as a smell, a song or a particular sentence.

Barzykowski's research team, which tested KCL remotely because he lived far away, confirmed that the teen did indeed have HSAM. His memory was statistically expected to exceed that of 99.9 per cent of the general population, ScienceAlert reported.

Not Superheroes

However, Barzykowski said that people with HSAM are not cognitive 'superheroes'. In fact, most of them, including KCL, have normal attention, working memory and executive functioning.

"On the contrary, they appear largely comparable to the general population in domains such as learning everyday information or memorizing numbers. What distinguishes them is the way in which they remember and access autobiographical events – information about what they have experienced, witnessed, and lived through."

Nothing unusual was found in KCL's brain, and his parents reported no psychiatric or educational issues, according to the report.

The report also noted: "Compared to existing data from ordinary folks, KCL had a 'markedly elevated' frequency of involuntary autobiographical memories arising during his tests. But this only applied to thoughts about his own past. Spontaneous thoughts relating to the future were in a normal range, as was his overall frequency of task-unrelated thoughts."

The research has been published in the journal Cortex.