Janet’s Law
Today is August 4, 2026 (Tuesday). This year has already entered its second half, and in the middle of this summer heat, I find myself thinking, “Wait, it’s August already?” Maybe it’s my age—50—but a year just feels like it passes so fast. It seems to be speeding up more and more as I get older, so, out of curiosity, I looked it up.
What came up was something called “Janet’s law.” It was proposed by Paul Janet, a 19th-century French philosopher, and apparently explains a psychological phenomenon where the subjective length of time a person feels is inversely proportional to their age. It’s less a strict scientific law than a theory that captures the feeling well.
A year at 50 is 1/50th of a life lived so far, while a year at age 5 apparently felt ten times longer—one-fifth of a life. In other words, I’m experiencing time ten times faster now.
As children, everything is a first-time experience, so the brain processes a huge amount of information and stores it as vivid memories—which is why looking back, it feels like “so much happened.” All those memories stack up, and as a result, that time feels long. As adults, though, more of what we experience is already familiar, so the brain shifts into an “energy-saving mode,” and looking back, there’s less data of memory to draw on, which makes it feel like time “flew by.”
I don’t have vivid memories from when I was five, so I can’t make a clean comparison, but it does seem true that time starts to feel faster as we age.
Still, even though I understand it as a psychological phenomenon, I don’t think it’s simply a matter of “getting used to things and going into energy-saving mode” in my case. I think it’s more that taking on something new every day, and staying immersed in thinking and making things, is actually what’s speeding time up. Because I keep having these focused days, the boundaries between weeks disappear, and before I know it, the month has changed.
Maybe the fact that time feels like it’s passing quickly isn’t a sign of thin memory, but proof that I’m living through time that’s dense with experience. Five months left in the year. I’ll just try to hold back the urge to rush, and take care of each day as it comes.