We've all been there before: you snap out of a daze, look around, and realise you've driven all the way to your destination without really noticing it. It's a scary but common experience. Here's what's going on.
The idea that we can forget about large chunks of time is unsettling, but it really just boils down to how we perceive time in general. In this particular case, it's about how time and memories are formed together. Neurologist David Eagleman uses this common example of the workday commute:
And that's of course what happens during a typical workweek or when you drive to work. You’re doing something that you do all the time. Time shrinks retrospectively. But if you go off for the weekend to some novel vacation, a place you’ve never been before, then you look back and you think, "Wow, that was a very long weekend!"
The reason is simple: the longer it takes for our brain to process information, the longer the period of time feels. So when the brain isn't doing a lot of processing, which happens on your unchanging commute to work, it doesn't feel like a long period of time.
One study from the Journal of Consumer Psychology suggests that the more attention we pay to an event, the longer the interval of time feels. Another study from the Journal of the Association for Psychological Science had similar findings.
It makes sense too. Think back to the last really great day you had. Chances are by the end of the day, you felt as if several days had passed since you ate breakfast. Now think back to that morning commute. Despite the fact you were actually stuck in congested traffic and bored for much of it, it likely feels really short.
Speaking with David Eagleman, The New Yorker describes how memories and the perception of time work together like so:
"This explains why we think that time speeds up when we grow older," Eagleman said — why childhood summers seem to go on forever, while old age slips by while we’re dozing. The more familiar the world becomes, the less information your brain writes down, and the more quickly time seems to pass.
Essentially, new experiences make it feel like time passed more slowly. In the moment, that commute may have felt like it was taking forever, but when it's done, it felt like it flew past. Think of it as though your commute has just a few prints of film in it to fill up a whole hour. When you play it back, you can watch the whole thing in 10 seconds. Now, think about that great vacation, all those memories fill up a lot more film, and thinking through those memories takes a lot longer than the commute. Effectively, that makes us perceive that time is actually extended.
So, how do you actually remember your commute? You'll need to recalibrate your reality a little and pay attention to the world around you. As we've mentioned before, you can increase your powers of observations with practice, and when you break out of your comfort zone you'll inevitably create a new set of memories that help you parse time better. Our attention is valuable, and when you use it to create memories, you're effectively making it seem like time stretches out. When you don't, it just flies by like your boring commute.