If you spend too much time thinking about a thing..............

 We have a strategic plan. It’s called doing things, Herb Kelleher, American billionaire airline executive and lawyer

"He who works all day has no time to make money." - John D. Rockefeller

I think both this phrases are right. I see more trouble from people who think & think & think and don't start. The people who don't think a lot and just execute turn out to do better than the thinking ones.