more: The regions of the brain that become active during mind wandering belong to two important networks. One is known as the executive control system. Located mainly in the front of the brain, these regions exert a top-down influence on our conscious and unconscious thought, directing the brain's activity toward important goals.

Of all the ways to let your mind wander, zoning out is considered to be "the most fruitful type." It was also found that sad thoughts allow for more wandering than happy ones. In either case, wandering may help the mind search and find solutions more effectively than constantly trying to keep it in focus.

They could have found this out earlier if they weren't so happy condeming people for being inattentive.
-bitter ADD person (ok....I'm really not that bitter)