These authors suggest that attention plays an important role in creating boredom. In particular, there are a few conditions that need to be met for people to feel bored. First, people need to have a reasonable level of psychological energy or arousal to feel bored. When people have low arousal and there is not much happening in the world, then they often feel relaxed. When they have high arousal, though, they have energy they would like to devote to something, but they cannot find anything engaging.

Boredom is similar to mental fatigue and is caused by repetition and lack of interest in the details of our tasks (such as tasks that require continuous attention, waiting at the airport, prisoners locked in cells). Any experience that is predictable and repetitive becomes boring. In general, too much of the same thing and too little stimulation can cause in its victim an absence of desire and a feeling of entrapment (Toohey, 2012).    
Finally, a real problem caused by boredom is that it leads you to dislike the things that are the object of boredom. In my senior year of high school, for example, I was forced to read Moby Dick. I struggled to get interested in it and spent long hours staring at the pages trying to lose myself in it. To this day, I really do not like Moby Dick. The negative feelings that came with the boredom have stuck to the book.
There was also a piano, well littered with music, a sewing bag thrown down upon a cretonned window seat, and the generous fireplace was flanked by two huge baskets, one heaped with magazines, the other a perfectly round mound of yellow fur, which suddenly took form and life as a yellow tabby cat fastened hopeful topaz eyes upon them, blinked away a brief disappointment, and then yawned with ennui.