Mind-wandering is often viewed as a mark of unproductivity, lack of control, even laziness. But in a healthy mind it’s normal, helping the brain quietly cogitate on experiences and plan next moves.
Einstein is said to have come up with his theory of relativity while daydreaming. You may not be an Einstein, but surely you’ve experienced your own little unexpected epiphanies, those light-bulb moments when you’re not thinking about the thing you were trying to think about and suddenly the answer pops into your head. Maybe in the shower, while walking or driving, or during a workout… More here.
I have always thought that I daydream too much and that it gets in the way of real life. Perhaps, however, there is an upside after all.