My fingers hurt.<p>I doubt it's exclusively to do with time as fraction of life. I suspect it's more to do with novelty: when you're young, much of what you see is new so you take it in and mull it over with some awareness. As you hit your working life, days can blur together as you engage in the same sort of tasks over and over. Later, as you reach mid career, most situations you encounter similarly become routine and you don't notice stuff which may have been remarkable a few years before. The effect is that you don't notice the weeks and months whipping by, since much of it is tuned out by your ever-growing filters.<p>Thinking more, I wonder if there aren't two effects at work: one is the fractional piece the presentation talks about: that's what makes being asked to wait five minutes seem intolerably cruel to a four year old. Then, the sense of time speeding up in adult life is caused by the growth of experience and dearth of novelty.<p>Explains why travel keeps you young and a change is as good as a vacation.