Time flies when you’re having fun, but time flew when you were bored.

The last few weeks at work have been incredibly busy. Each day, I feel like I get to work, and the next thing I know, it is time to get home. The days feel like a blur. It has been so busy, I haven't even had time to put up any blog entries. It has been a few weeks since the last one. It feels like it has been a very long time since the last time I wrote an entry.

That is a bit strange, though. If each day has flown by, why does it feel like it has been a long time since I last wrote an entry? Shouldn't the entire period feel like it has flown by?

There is some nice research by Dinah Avni-Babad and Ilana Ritov in the Journal of Experimental Psychology: General that addresses this question. They find that people judge the duration of a period of time from memory differently than they judge the duration of a time period as it is going on.

Basically, the busier you are during a time interval, the faster that time interval will feel like it passed. That shouldn't be surprising. We all know that time flies when you're having fun. When you are cognitively busy, you are focused on each task you are performing, and so you don't have the opportunity to notice the passage of time. As a result, the interval feels like it passes quickly. When you are bored, there is not much to occupy your time, and you are much more likely to think about the passage of time. So time feels like it passes slowly when not much is happening.

When you look back on time periods, though, things reverse. How can you decide how long a time period was in retrospect? You have to retrieve events from memory in order to judge durations. When you think back on an interesting time that had lots of new experiences, you are able to retrieve a lot of events from memory. So, interesting time periods feel like they have taken a long time. In contrast, boring time periods do not add much new information to your memory. As a result, when you think back on those boring or routine periods of your life, they will feel like they flew by.

I guess the mark of a successful life, then, is that the days have flown by, but the years feel long and full.