This is not imagination. It is a well-documented psychological phenomenon with a clear mechanism. And understanding it may be more practically useful than any productivity system or time management framework.
The Proportionality Hypothesis
The dominant explanation for why time seems to speed up with age is called the proportionality hypothesis, proposed by psychologist William James in 1890 and developed by researchers since.
The idea is simple: we experience time relative to our total lived experience. For a 10-year-old, one year represents 10% of their entire life — a substantial fraction, rich with firsts and novelty. For a 50-year-old, a year is 2% of their life. The same 365 days registers as proportionally smaller.
This is why childhood summers feel endless and why your forties can seem to pass in a blur. The calendar does not change; the ratio does.
The Neuroscience of Memory and Time
Psychologist Marc Wittmann at the Institute for Frontier Areas of Psychology has studied time perception extensively. His research points to a closely related mechanism: memory density.
The brain constructs its sense of how long a period lasted based largely on how many distinct memories it can retrieve from that period. Novel experiences — new places, new people, new challenges — create more memory checkpoints. Routine, repetitive experience creates fewer.
This is why a two-week trip to a foreign country feels much longer than two weeks at home. It is not that the trip lasted longer. It is that your brain encoded more distinct moments — and those moments, retrieved in memory, feel like they took up more time.
The implication is significant: a life full of novel experience is, in subjective terms, a longer life.
The Harvard Wandering Mind Study
In 2010, psychologists Matthew Killingsworth and Daniel Gilbert published a study in Science using a smartphone app to sample people's mental states at random throughout the day. They found that participants' minds were wandering — not engaged with the present activity — approximately 47% of the time.
More importantly: mind-wandering was consistently associated with lower happiness, regardless of what the person was actually doing. Being mentally present while doing something dull was associated with higher wellbeing than being mentally absent while doing something pleasurable.
Time, in other words, is not just lost to distraction. It is worse than lost — it registers as unhappiness.
What Eckhart Tolle Adds
Tolle does not frame this as a psychology problem with a psychology solution. He frames it as a structural misunderstanding about time itself.
In The Power of Now, he argues that what we call "past" and "future" do not actually exist as experienced realities — only as thought. The past is a memory arising now. The future is an anticipation arising now. The only place anything ever actually happens is the present moment.
"Nothing ever happened in the past," he writes. "It happened in the Now. Nothing will ever happen in the future. It will happen in the Now."
His point is not to dismiss the past or deny the future. It is to recognise that the only place you can actually live — the only place experience happens — is here. And that choosing to be present, even briefly, is not an achievement to chase but a recognition of something already true.
The Practical Implication
Wittmann's memory research and Tolle's philosophy land in the same place from opposite directions: presence creates more life. Not more calendar time — more experienced, encoded, retrievable, meaningful time.
More novel experiences. Fewer days on autopilot. More moments where you are actually where your body is.
The years will still pass. But there will be more of you in them.
Your Time So Far
The Life in Numbers calculator shows your exact count of days, hours, and seconds since birth. Use it not as an anxiety trigger, but as a reminder: the number is moving right now, in this moment. So are you.