It’s not just a bromide; time actually does seem to move faster as we get older. When you were a kid, summer seemed to last forever, and school seasons lasted even longer than that. Now, not so much. There’s an hypothesis about that, and it has to do with attention: as you habituate to things, your brain kind of goes into autopilot mode as an energy-saving feature. Human brains burn a lot more calories when running when compared to those of most other animals, and learning stuff means you’re burning more. Want to lose weight? Learn new stuff every day.
Kids don’t spend nearly as much time on autopilot, as a rule: because they’re young and inexperienced, most of their days are filled with new learning experiences, building new neural pathways. And that makes time appear to move slowly. The advantage of autopilot is that it conserves energy; the downside is that you don’t pay attention to as much, and so with fewer reference points, time seems to move much faster than it did back in the day.
Oh, there are some other physical aspects to your perception of time as well; without getting too far into the weeds on this, dopamine affects your perceptions, and levels of that neurotransmitter drop as you age. You can boost that by smoking rope, which will definitely act to make time seem to slow down. But the major component in terms of the speed of passage of time seems to be down to attention – the more you’re on autopilot, the faster time seems to go.
As for me, I’ve always paid a fair amount of attention to detail, which may partly explain why I’ve never topped 160 pounds. Whether coding or training or fishing or wood-cutting or whatever, it seems that there’s always something new to learn. It stems from the early days of childhood, when it occurred to me that I wasn’t especially wanted after noticing that my bath toys were a toaster and a radio.