qwerty456127
Because working days don't count as living (days spent worrying also don't so being jobless hardly helps). Only secure spare time is life time. After all the chores you have to do besides your job, an average adult doesn't have much time to live. A day per week max. Even if you have full 2-day weekend for yourself you still need a day to recover a bit from the burnout before you can really live. This said, count how many days of life do kids get per annum and how much do adults get. Many don't get any.
boricj
From what I've seen, perception of time depends a lot on how much time one has experienced. Five years is a quarter of the time experienced by a 20 year old, but not even a tenth for a 60 year old.
jajko
Memory lossy compression, keeping us sane. Why on earth would evolution want us to remember last month what we did on 16th, when the day looked exactly same as 15th and 17th? What about same dates but 15 years ago? Absolutely meaningless.

Do novel new intense things in your life, at literally any age, and you will remember them very well, and the feeling of how much time passes will change dramatically, I call it personally 'adding decades of life felt'.

When I did my 2 stints of 3 months backpacking all over India (and a bit of Nepal) around age 30, I wasn't prepared. Every day completely different than previous one, no strict plan just massive Lonely planet book and return flight ticket in 3 months, no phone, no credit card (2008 and 2010).

After few weeks, I felt like I was on the road for 6 months. After 2 months... hard to describe by mere words - the entire life back home, didn't matter which part or when, felt like literal memory of a dream you had last week, very hazy, somehow it felt real since I went cca 1x a week into internet cafes to check emails and yes those were my parents writing back, but were they? It felt brutally distant, and Indian/Nepalese reality felt like the only truth, that always was and always will be. Literal different life with reborn moment somewhere on a plane there.

I managed to recreate exactly same experience on a second visit, 100% since I behaved in same fashion. Much shorter stint in Tanzania afterwards lasting 3 weeks achieved milder effect of it - say it felt like 3-6 months on the road, its not linear how it scales. Did Kilimanjaro for 1 week, Serengeti/Ngorongoro another one, and last week on Zanzibar (way before it became cheap european holiday destination). Again, the key was novelty.

I still remember so many events, people, places etc. from those trips like it happened yesterday. I came back different, and made changes in my life for better, much better. Looking back, it was literal life (re)defining moment. I don't think I can recreate it easily these days, it would have to be done without phone again. But going there into some luxury resort, none of that would happen, its not about distance but how far out of your comfort zone you push yourself out for a long period.

iJohnDoe
I think age has affect on the brain.

Primarily, if I had to guess, it’s simply what we’re experiencing that makes time feel slower or faster.

Having fun? Time goes by faster.

Boring class? Time goes by slower.

Up all night with a newborn? Those first couple of years feel like a long time.

When that newborn is older and now you’re playing video games, riding bikes, and having fun? The saying goes, “They grow up too fast.”

29athrowaway
When you fall into a routine, you tend to compress all of the instances of that routine.
randomdata
Because childhood is spent waiting to become an adult. Everything is forward looking with the desire to get to experience the next big thing, which gives the impression of a long wait. In the micro you can experience the same as an adult by standing in a long lineup waiting for something you want. That wait in line will feel like it takes forever. But, in the macro adults stop wanting the future to come.
stranded22
It is the repetition of life experiences.

Like how Christmas comes around slowly when you are a kid, but each year it speeds up a little because life has lost its new-ness. So then, your brain takes short cuts - like how when the first journey somewhere takes AGES, but after a few times, it feels a lot quicker (whilst being the same physical time)

qwerty456127
It freakin speeds up every year, never stopping, almost exponentially!
phkahler
When I was little (according to my older siblings) I referred to any past event as happening "yesterday" and anything coming up as "tomorrow" even if it's next week or month.
timonoko
I distinctly remember my shock when I realized the "winter" was coming again. Previous year was thus my whole experienced life-time.

The winter 1956 was indeed difficult in Finland. Because of general strike and Hungarian Uprising elementary things like Milk and Kellog's Corn Flakes were in short supply.

User23
There’s clearly a relationship between the perception of time and memory formation. For example when undergoing heavy sedation, such as for surgery, the time between going under and coming to feels instant. Of course you’re a bit loopy thereafter, but the time when you’re forming absolutely no memories at all is a skip.
drooby
I'd like to propose the idea of synaptic pruning.

The brain may have up to 50% less neurons in adulthood than in infancy.

A child is simply experiencing more stuff at each moment of time than adults.

Because, their brain is actually firing more neurons, many of which might be redundant executions. Hence.. the need for pruning.

throwaway98797
8th grade is when time speeds up

that is when you become aware of the repetition and rhythm of life

further the less compressible life is the longer it seems

same job for 10 years feels fast since nothing happens, but different jobs every year (good or bad) makes time seem long since there’s so much to remember

also the less you sleep the less you feel alive

begueradj
Also interesting to check the arguments shared here (Why time speeds Up as you age):

https://www.youtube.com/watch?v=bx-3hS1n0v8

rowanG077
If I look back at my childhood I don't particularly have a feeling of time moving slower as a child. I have heard this so often but I don't have the same experience. Perhaps my memory is just too bad.
amriksohata
Article doesn't speak of brain waves, a childs brain waves are in an almost dream like state and absorb everything like a sponge.
johnea
Why do we keep seeing this topic?

It has to be due to how many HN readers are themselves children...