> This may be why time seems to speed up as you age: you develop more compressed representations of events, and the memories to be read out are correspondingly impoverished. When you are a child, and everything is novel, the richness of the memory gives the impression of increased time passage—for example, when looking back at the end of a childhood summer.

With no proof or otherwise, I had always conjectured that this was because time is compared proportionally. When I was 6, the three months of summer were approx 3 / 72 of my life = 1 / 24. When I am 60, those three months will occupy 1 / 240 of my life.