Say, John, a high school student, is reprimanded by his Maths teacher to "stop daydreaming and pay attention in the class". Now technically, the teacher is right for rebuking John, as it is John's duty to concentrate on the subject at hand, and not drift away thinking of something else. But, there is more to daydreaming than it being mere drift in thoughts. Let us assume some possible reasons why John daydreams in his Maths class: