Why time feels like it's accelerating as you get older: and the science of slowing it down

The universal mystery: where did the year go?

Every autumn, a lot of adults have the same small jolt. You look at the calendar, see that it's October, and wonder where the year went.

Think back to childhood. A single summer vacation between school grades felt like an entire epoch. You learned how to swim, built treehouses, scraped your knees, made new best friends, and lived through enough distinct adventures that three months felt long enough to alter your entire identity.

In adulthood, the exact opposite occurs. January arrives, you blink, and suddenly you are putting up holiday decorations again. Weeks dissolve into months, and years collapse into an indistinguishable fog of commutes, email threads, grocery runs, and routine obligations.

The feeling is real, and people have studied it for well over a century. No single explanation covers all of it, but several ideas help, and some point to things you can actually do.

Theory 1: The proportional theory of time (Janet’s Law)

One of the oldest explanations comes from the French philosopher Paul Janet, who proposed it in 1877 (William James later helped popularize it). Janet argued that our perception of a given period of time is proportional to the total length of life we have already lived.

Consider the mathematics of a single year from different vantage points:

When a child turns five years old, a single year represents a staggering 20 percent of their entire conscious existence on Earth. Experiencing 365 days means adding one-fifth to everything they have ever known.

When a teenager turns twenty, that same year represents only 5 percent of their life.

By the time an adult reaches fifty, a year is a mere 2 percent of their accumulated life span. A single day represents an infinitesimally tiny sliver of their total cognitive database.

On this view, a year feels shorter the longer you have lived. It is a neat idea, but it is a rule of thumb and not a measurement, and the brain's timekeeping is more complicated than a simple ratio.

Theory 2: Neural processing and saccadic "frames per second"

In 2019, Duke University engineering professor Adrian Bejan published a paper titled 'Why the Days Seem Shorter as We Get Older.' He approached the question through physics rather than psychology, and his proposal is a hypothesis that other researchers have not settled.

The idea starts from the observation that we don't sense time directly. We notice changes in what we see and feel, which you can picture as frames in a film.

Bejan argues that children's nerve pathways are shorter and their eyes make more rapid small movements (saccades), so they take in more of these 'frames' in the same amount of time.

As the body grows and ages, he suggests, signal paths get longer and slower, so signals take a little more time to travel from the eye to the brain.

If that is right, an adult processes fewer 'frames' per hour, and a day with fewer of them could feel shorter in hindsight. Treat this as an interesting hypothesis, not an established finding.

Theory 3: The Holiday Paradox and routine compression

To truly understand why your years vanish, you have to separate prospective time (time as you are living it right now) from retrospective time (time as you remember it in hindsight).

British broadcaster and psychology writer Claudia Hammond calls this disconnect 'The Holiday Paradox.'

Think about what happens when you spend five days in a brand new foreign city. In the moment, your prospective time may feel rapid because you are constantly engaged: navigating subway lines, tasting unfamiliar spices, reading street signs in another language, and taking in new architecture. Yet when you return home on Sunday night and look back, those five days feel like three full weeks of lived experience. Your mind is overflowing with distinct landmarks.

Now consider the reverse: a routine work week where you wake up at 7:00 AM, commute the same route, sit at the same desk, answer similar emails, eat lunch from the same deli, and watch television on the sofa. In the moment, prospective time drags on painfully slowly. Tuesday afternoon feels endless. Yet when you look back on that week on Friday evening, it has compressed into a single, contentless cognitive file. You cannot remember whether you had soup on Tuesday or Wednesday.

Memory researchers generally agree that we remember distinct events better than repeated ones. If day 180 looks a lot like day 179, there is little to tell them apart later, so they tend to blur together. A year of predictable days can end up feeling much shorter than a year with plenty of new experiences.

Theory 4: The Reminiscence Bump and the drought of firsts

In 1890, William James wrote in The Principles of Psychology:

'In youth we may have an absolutely new experience, subjective or objective, every hour of the day... But as each passing year converts some of this experience into automatic routine which we hardly note at all, the days and the weeks smooth themselves out in recollection to contentless units, and the years grow hollow and collapse.'

Memory researchers, including David Rubin and colleagues, have documented what is called the 'reminiscence bump.' When adults over the age of sixty are asked to recall the most vivid memories of their lives, their recollections are disproportionately clustered between the ages of 15 and 25.

Why does this period stand out so much? One likely reason is how many 'firsts' it holds: your first driver’s license, first job, first heartbreak, first apartment, graduation, moving away from home, and early professional struggles.

By your thirties, forties, and fifties, the natural density of firsts plummets. You know how to drive, how to pay bills, how to manage your job, and where you buy groceries. Without some effort, adult life can slide into autopilot, with fewer vivid moments for memory to hold onto.

The cognitive antidote: 4 scientific principles to slow down time

You can't slow the calendar. You can change how much of the year you remember.

Here are four ideas, drawn from the research above, that can make a year feel fuller in hindsight:

1. Build intentional autobiographical landmarks: German cognitive psychologist Marc Wittmann emphasizes that temporal landmarks act as mental buoys in the river of time. If you do not create deliberate markers, the current sweeps everything away. You do not need to quit your job and travel the world; you simply need micro-novelty. Take a completely different walking route, cook a complex cuisine you have never attempted, visit a new neighborhood on Saturday morning, or read books in unfamiliar genres. Small novelties give your memory something new to hold on to.

2. Escape the digital camera roll amnesia trap: Many people believe that snapping thousands of smartphone photos protects their memories. In reality, psychologist Linda Henkel's research on the photo-taking impairment effect suggests the opposite can happen. In her museum study, people who photographed objects remembered fewer details than those who simply looked. Photos also pile up: a library of 30,000 uncurated pictures rarely gets looked at again.

3. Establish a recurring monthly reflection cadence: Trying to recall a whole year in December is hard. Pausing for fifteen minutes at the end of each month to ask, 'What actually mattered over the last thirty days?' is much easier. Picking two or three moments and writing a short note helps you remember them while the details are fresh.

4. Give your memories a physical, bounded home: Human-computer interaction researchers Daniela Petrelli and Steve Whittaker found that families build up large digital archives that mostly go unlooked-at, while physical keepsakes on display tend to start conversations and shared remembering. A printed photo on a wall, a scrapbook, or an annual book has edges and a place in the home that a screen doesn't.

Three ways to build an annual anchor (and where yeerbook fits in)

Once you understand that slowing down time requires structured reflection and physical boundaries, the question becomes practical: what is the best system to actually keep this habit alive year after year?

Here is an honest breakdown of the three most common approaches, their trade-offs, and why different methods work for different people:

Option 1: The analog memory box or scrapbook

How it works: Keep a dedicated archival box or binder in your home. Throughout the month, drop in physical ticket stubs, handwritten notes, postcards, and print 4x6 snapshots using a local print shop or an instant photo printer.

The trade-off: It is tactile and personal, but it takes supplies, storage, and steady discipline. Many busy people find it stalls by spring or summer.

Option 2: The traditional year-end photo book marathon

How it works: In late December, sit down in front of a traditional photo book platform (such as Mixbook, Shutterfly, or Blurb), export thousands of photos from your phone, and manually drag and drop them into custom digital layouts.

The trade-off: You end up with a printed book, but sorting thousands of photos and laying out dozens of pages can take many hours, and it tends to land in the busiest part of the year. Plenty of people leave the draft unfinished.

Option 3: The low-friction monthly cadence (why we built yeerbook)

How it works: Instead of a frantic 20-hour sprint in December, you take 15 minutes on the last Sunday of each month. Each month, yeerbook prompts you with thoughtful questions, you select two or three favorite photos, and write a quick reflection or record an audio note. Over 12 months, your book compiles itself automatically. At the end of the year, a 21x30 cm hardcover printed on archival-quality paper arrives directly on your doorstep.

Why it fits: We built yeerbook for people who want a physical keepsake but don't have time to become a part-time graphic designer every December. It makes memory-keeping a small monthly habit instead of a seasonal chore.