Summer is here. School is ending for the year, and school kids are looking forward to a few months of doing nothing. Even for those of us who are out of school, there is something about summer that makes us want to shut down a bit. Maybe we learn it from the academic schedule that we keep for the first quarter of our lives.

The interesting thing is that this way of thinking about school reinforces a dangerous view of learning -- dangerous because most of us don't realize how much it influences our behavior.

Deep down, most of us think of learning as something we do in classes and lectures. We also focus on learning things that we think are going to be relevant for something that we're doing right now.

This summer, it is time to open up. Here's why.

You never know where your next good idea is going to come from. Lots of your good ideas come from things we have learned specifically to solve particular problems. You might take a cooking class to learn to prepare a particular kind of food. You might take a music lesson to play a particular musical instrument.

Classes are great ways to pick up new knowledge and new skills. And often those knowledge and skills can be put into practice right away.

But sometimes the things you learn don't turn out to be important until much later. I know that when I was in school, I was never entirely sure why I was learning about historical events that happened hundreds of years ago on another continent. But years later, that knowledge has turned out to be useful for understanding references in books and movies.

More importantly, though, you don't necessarily need to believe that you are ever going to need something you learn to have it become important for you later. To see that, think about vacuums.

In the late 1970s, James Dyson was vacuuming his floors. He noticed that after a while, the vacuum would lose suction. The vacuum loses suction as the bag gets full. So, most of us solve this problem by changing the bag and continuing to vacuum as usual.

Dyson was different, though. He was interested in gadgets of all kinds. He thought about what a vacuum is doing. It sucks dirt and air into it and then it has to find a way to separate the dirt from the air. Most vacuums do this by creating a bag that acts as a filter. The air blows through the bag, but the dirt stays inside. Eventually, the dirt clogs the pores in the bag and the vacuum doesn't work effectively.

One of the things that Dyson knew about was the way a sawmill works. As it turns out, sawmills have to solve a problem that is similar to the one that a vacuum solves. When you mill a log, it generates a lot of sawdust. The way a sawmill solves this problem is by using an industrial cyclone. Air gets sucked into the top of a cylinder. The flowing air creates a cyclone, and the sawdust gets pushed outward by centrifugal force. The sawdust slides down the cylinder into a hopper and the sawdust-free air flows out.

Dyson went to his workshop and spent a few years designing a miniature industrial cyclone that could fit in a vacuum cleaner. His company has sold millions of dollars worth of these vacuums.

The key, though, is that Dyson did not know that some day he would really need to know how an industrial cyclone works. He was just curious. And when the day came where that knowledge was useful, he was ready.