When I was a child, the distance between one birthday and the next felt enormous. Now entire seasons seem capable of slipping past while I am still mentally filing the previous one. The calendar has not become more efficient, but it can certainly feel that way.
I am a writer, not a clinician. This is reporting and interpretation, not medical advice.
There is a wonderfully simple explanation for the feeling. One year is a fifth of everything a five-year-old has lived, but only one fiftieth of a 50-year-old’s life. Polish linguist Joanna Szadura argues that this shrinking ratio may matter because our internal scale of time is nonlinear, even though the clocks and calendars around us are linear.
The arithmetic is indisputable. The psychology is not. This is one study, not settled consensus, and the brain-imaging work that prompted Szadura’s comment did not test whether people actually calculate years as fractions of their lives.
A true calculation can still be an untested explanation
Szadura, a professor at Maria Curie-Skłodowska University who studies time in language and culture, made the comparison in an October 2025 interview with Live Science. She described two scales. Society divides time evenly into seconds, days and years. Subjective time, she suggested, follows something closer to logarithmic laws, with equal calendar intervals taking up progressively less space as experience accumulates.
This family of explanations is often called the proportional or ratio account. At five, one year is 20 percent of life so far. At 50, it is 2 percent. Relative to the whole, the later year is one tenth the size.
It is a satisfying idea because the numbers make an elusive feeling visible. But a mathematical relationship is not evidence that the brain uses that relationship. The calculation does not tell us whether a year actually feels shorter while it is unfolding, whether it merely looks shorter in retrospect, or whether both judgments are being shaped by something else.
The brain study did not ask people how fast time felt
The scientific paper behind the news was led by Sofia Lugtmeijer and published in Communications Biology on September 30, 2025. The researchers reanalyzed fMRI recordings from 577 adults, aged 18 to 88, who watched an eight-minute edit of the Alfred Hitchcock television episode Bang! You’re Dead.
Rather than asking people to estimate duration, the team used an algorithm to find transitions between relatively stable patterns of brain activity. Think of these patterns as neural scenes. The movie continues without stopping, but activity settles into one state and then changes as the brain processes what happens next.
Older participants tended to have longer neural states. Their brains moved into new states less frequently, and some of the boundaries between successive states were weaker. The effect was especially visible in the visual cortex and the ventromedial prefrontal cortex. The authors described the pattern as temporal dedifferentiation: neighboring moments were represented less distinctly at the neural level.
In their published paper, the researchers proposed that fewer neural state changes in a fixed period might contribute to older adults experiencing time as passing more quickly. If experience is divided into fewer distinct pieces, the period may later seem less densely filled.
But the participants never reported whether the film felt fast or slow. The study used one movie, and the conscious boundaries people perceived between its major events remained broadly stable with age. Even the authors say the connection to everyday time perception needs to be tested. The scans found an age-related neural pattern, not the cause of vanishing summers.
Age matters, but mostly when we look across long stretches
The wider evidence is more interesting than the slogan that time simply speeds up with age.
In 2005, Marc Wittmann and Sandra Lehnhoff asked 499 people, ranging from 14 to 94 years old, about the passage of time. Their results generally supported an age-related acceleration, but the effects were small to moderate and accounted for no more than 10 percent of the variation. Plenty of people at the same age experienced time differently.
Another study, published in Time & Society in 2013, asked 868 participants how fast the previous week, month, year and ten years had passed. There was no age effect for the week, month or year. It appeared only for the decade. Current time pressure predicted faster judgments over shorter periods, while remembered time pressure was related to how quickly the preceding decade seemed to have gone.
That difference between intervals is easy to miss. A 70-year-old does not necessarily experience every Tuesday as moving faster than a 20-year-old does. The clearer age pattern emerges when people stand at a distance and judge whole chapters of their lives.
The time we live and the time we remember are not identical
Psychologists distinguish prospective judgments, made while we are paying attention to time, from retrospective judgments made after an interval has ended. The distinction explains some everyday contradictions.
Waiting in an airport can crawl minute by minute, then leave almost no trace when we look back. A holiday may seem to race past while we are enjoying it, yet occupy a wide stretch of memory afterward because it contains new places, conversations and visual scenes. This is sometimes called the holiday paradox.
Routine can reverse the pattern. Familiar days may pass comfortably enough, but because they share so many features, memory has fewer reasons to preserve each one as a separate event. A month of similar commutes and meals can later collapse into a compact summary.
I wrote recently about how a song can become a strong cue for rebuilding an autobiographical memory. “Rebuilding” is the useful word. Memory is not a video file that preserves every day at its original duration. When we judge how long a period felt, we are reconstructing it from the scenes, changes, emotions and landmarks that remain available.
Why the 20-percent explanation cannot carry everything
The ratio account gives subjective time an elegant curve, but it contains a hidden assumption: the mind must evaluate the current year against the entire life lived so far. Researchers have not established that this implicit division is what people do.
If ratio were the whole mechanism, age should predict the feeling with unusual regularity. Instead, judgments change with the interval being considered, attention, time pressure, routine, memory density, emotion and what the period meant to the person.
A 2026 review in Frontiers in Psychology by Mark Landau and Young-Ju Ryu argues for a broader view. They call these retrospective impressions “life-tempo judgments” and stress that they are not literal perceptions of clock speed. Their review finds no single established mechanism that explains judgments across weeks, years and decades.
The authors group together several possible influences. Some are cognitive, including routine, attention and memory compression. Others concern meaning, personal growth, nostalgia, cultural expectations and the standard against which we decide life moved “too fast.”
One result is almost poetically inconvenient: periods remembered as meaningful, engaging or full of growth can also be remembered as having passed quickly. Fast-feeling time is not necessarily empty time. Sometimes a period feels fleeting precisely because we wanted more of it.
A mosaic of clocks is more plausible than one master clock
My reading of the evidence is that the fraction-of-life calculation belongs in the explanation, but not alone. It supplies a possible scale for comparing years. Neural dedifferentiation may affect how finely ongoing experience is divided. Novelty and routine alter what memory stores. Attention and time pressure change the feeling of an interval as we live it. Culture supplies birthdays, school years and other markers that help us organize the story afterward.
Different mechanisms may dominate at different scales. That is how a dull afternoon can feel endless, a busy month can vanish and a decade can seem both enormous and impossibly brief. None of those judgments requires the others to be false.
It is tempting to end with a recipe for slowing life down, but the research is not firm enough for one. Novel experiences can make a period richer in memory, yet meaningful and engaging periods may also feel fast. A quick-feeling year is not evidence that it was wasted, and it is not a diagnosis of a failing brain.
The calendar is linear because we designed it to be. Lived time is assembled from attention, memory, biology and meaning. Szadura’s arithmetic gives that compression a beautifully clear shape. It does not close the case, but it helps explain why every year can contain the same number of days and still refuse to feel the same size.
