Thinking too much can only cause problems.

Day Dream Cause Man Failure

Everybody must avoid daydreaming, but this is especially necessary for workmen in factories. There are four common kinds of day dreams which make workmen careless and inattentive. The first is emotional daydreaming, like letting the mind dwell continually on the thrills of some strong emotion like love. A second is categorized by worry about imagined misfortunes, most of which never happen. 

Third is the kind of day dreaming due to retrospection; looking back on the pleasures or missed opportunities of the past. Last on the list are the day dreams of vengeance, in which the victim goes over and over again in his mind the terrible things he will do some day to some enemy or antagonist.