Teams of researchers have been working on this, and here's what they've come up with...
We all have things we do every day, exactly the same. The way we brush our teeth, the path we take the work, how we get ready for bed...
Well, according to Psychology Today, when we fall into these every day routines, our brains go into auto-pilot. And this gives us a sense that the day is flying by.
Dinah Avni-Babad is a psychologist at the Hebrew University in Jerusalem. She says that while we rarely remember routine actions, new experiences actually become imbedded into our memories. And it's these experiences that keep time from passing so quickly.
She says we should think of routine as a straight line in our memory. New experiences cause the line to zig-zag, changing our perception of things. But as we get older, we encounter fewer experiences, so the line straightens out and routine becomes the norm. That's why time seems to fly.
So how can you slow the clock? Our expert says to shake things up. Do one thing differently every day, and you won't grow old before your time.