By now you’ve probably seen this story floating around about how doodling may improve concentration, but I’m particularly interested in this part of the story:
When people are bored they have high levels of brain activity, Andrade says. “When you’re bored, you think nothing much is going on, but actually your brain is looking for something to do.”
So we daydream. But daydreaming takes considerable mental effort, particularly when we get stuck in a daydream. “So that sucks mental resources and energy away from the other task we’re meant to be doing,” Andrade says.
Which explains why we can feel so tired and burned out after a long, boring but easy day at work or school – or many successive days of boredom.