Most recent studies depict mind wandering as a costly cognitive failure with relatively few benefits (Mooneyham and Schooler, 2013). This perspective makes sense when mind wandering is observed by a third party and when costs are measured against externally imposed standards such as speed or accuracy of processing, reading fluency or comprehension, sustained attention, and other external metrics.
There is, however, another way of looking at mind wandering, a personal perspective, if you will. For the individual, mind wandering offers the possibility of very real, personal reward, some immediate, some more distant.
Via Ashish Umre