Scientists found brain’s internal clock that influences how we perceive time
arstechnica.com

Jennifer Ouellette, for Ars Technica:

Manmade clocks may precisely measure time, but, from a human perspective, the passage of time is remarkably fluid. It drags when you’re doing your taxes but really does fly when you’re having fun. Isolate yourself from any markers of time (night and day, watches or clocks) and you will feel less time has passed than actually has, because under those circumstances, the brain condenses time.