I think it is more than that. I think the perception of time is the rate of change of your brain state. Intuitively, this makes sense-- if I double the rate of

I think it is more than that. I think the perception of time is the rate of change of your brain state. Intuitively, this makes sense-- if I double the rate of your neurological activity, the world will seem to move half as fast. Similarly, if I freeze the activity of your brain and resume it some time later, you'd perceive no time to have passed. But I think it also applies on longer timescales, too, and to variations in the rate and degree the brain transforms itself-- If you repeat the same thing every day, your brain changes little, and those identical, indistinguishable experiences collapse onto each other in your brain's compressed representation. That is to say, if each week of your life is the same, the situation approaches one where I took your beginning-of-the-week brain state and transplanted to the end of the week without any changes. I should predict that under that circumstance you would not experience the passage of time. On the other hand, learning and experiencing dramatically new things forces your brain to change substantially, and the kind of cognitive delta that would normally occur over weeks or months of experiential stasis can happen in days or hours. Once people leave school, many years of routine can go by without many clear perceptual markers. I am noticing this in myself, and it's become a nontrivial motivator for making substantial life changes. Compounding this is the fact that neurology slows down as we age. I recall seeing a chart that suggested that a 60 or 70 year old will have roughly half (? maybe worse) the reaction time of a 20 year old. That suggests that 8 hours for a 20 year old would feel like 4 hours to a 70 year old. The study did not examine children under 18, but extrapolating the trend would suggest that children's brains are substantially faster still. Perhaps an hour for a young child is neurologically equivalent to 4 or 5 hours for a middle aged adult.