[itsdsmurrell]

This explanation misses a lot. When I watch an advert a second time, it seems to pass a lot faster than the first watch. My brain however has not changed at all. It seems that novelty is the main factor causing the perceived slowdown of time and that lack of novelty (less things surprise me as I age) makes time seem to pass more quickly. This also explains why staycations pass a lot faster than a trip somewhere new.