According to 7 Habits of Highly Ineffective People - Thinking too much without taking any action is bad. It makes your ineffective.
.."Paralysis by analysis can waste years of your life. There is nothing wrong with thinking before you do something. Do some research, make a plan, explore potential upsides and problems. But compulsively thinking and thinking and thinking is just another way to waste your time"..There have been so many ideas coming to me. I have been thinking and just thinking about them, but without any result. Will have to change. "Think and Act" should be my new year's resolution.