Why Does Time Speed Up as You Get Older?

Think back to a single summer as a child. It went on forever. Now this past year is a blur. That feeling is real, it is close to universal, and it is not about the clock at all. It is about how your brain records a life. You have two senses of time, and they disagree: time as you live it, and time as you look back on it. The speed-up of aging lives entirely in the second one. Part of it is arithmetic (a year is a smaller and smaller fraction of your life, an idea going back to Paul Janet in 1877). But the bigger culprit is memory: novel experiences lay down dense memories that feel long in hindsight, while routine collapses into almost nothing. David Eagleman's free-fall experiment proves it: even in terror, time does not actually slow down. The slow motion is a memory written after the fact. Which means the years are not really speeding up. You are just giving them less and less worth remembering, and the only known way to slow them back down is to keep finding things your brain has never seen before. Featured research: • Paul Janet (1877), recorded by William James, The Principles of Psychology (1890) — proportional theory • Claudia Hammond, Time Warped (2012) — the holiday paradox • Pariyadath & Eagleman, PLOS ONE (2007) — the familiar gets compressed • Stetson, Fiesta & Eagleman, PLOS ONE (2007) — the free-fall experiment • Adrian Bejan, European Review (2019) — the processing-rate hypothesis • Marc Wittmann, Felt Time (2016) #timeperception #neuroscience #psychology #memory #gettingolder