I was reading Kurzweil's The Age of Spiritual Machines last night when I stumbled across a tidbit that answered a question from my childhood that now seems fairly obvious. As a child, I remember pondering the nature of how time passes. I was intrigued by the fact that the first few weeks of school seemed to fly by when the last couple weeks of summer moved at a crawl. And, most importantly, how I could make the time I enjoyed move at a slower pace, giving myself more "time" to enjoy it. This kind of pondering dominated my childhood, probably to the point of compulsion at times and I often struggled with the fact that having only one piece of candy left rather than a pocketful could effect how I felt when I still had candy left in either case. The questions of which candy I ate first, last and the order in which I ate everything in between were constantly being reevaluated as well - they're just not as relevant.

Kurzweil is discussing the Law of Accelerating Returns with this fake "reader" character he has conversations with throughout the book and the reader mentions how time seems to be moving faster than when he was a child and how that seems to violate the law of accelerating returns. Kurzweil comes back with this absurd-sounding comment about how "the subjective experience is the opposite of the objective reality" which *does* actually make sense (amazingly) if you take a moment to weed through it. They eventually get to the point where they're talking about how time flies when you're having a good time and Kurzweil hits my childhood self with this bit:

"If someone goes through an experience in which a lot of significant events occur, that experience may feel like a much longer period of time than a calmer period. Again, we measure subjective time in terms of salient experiences."

So, duh. Summer tended to have a lot of the new and different going on while getting back in to the routine of school left very little room for something remarkable. I wish I could have had someone explain this to me when I was a kid though... To tie it in with recent times, the last two weeks of work have been full of salient experiences at the end of the day but the weeks themselves don't seem to have been longer than usual. Perhaps I can read on for more answers...