As a professional trader, I used to think that I needed to know every single detail about the markets I trade. When I first started I told myself that I had to be up on every fundamental report and every technical indicator. The problem was, the more that I knew, the more that the different signals or stories began to clash with each other. As a result I missed a lot of trades because instead of looking at what was right in front of my face, I over-analyzed it to the point where I had a reason against entering every trade I was suppose to enter. As a result I would miss opportunity after opportunity, only to look back in hindsight and realize that my first judgment call would have been highly profitable.
As an athletic coach I see some of my athletes make the same mistake on the day of competition. I often preach to them that the point of practice is to train our bodies to the point that when meet comes we don't have to think and can just do. Most people don't understand this, but thinking causes hesitation and in a sport like Track & Field especially a brief hesitation can mean the difference between winning and losing. The key is to train yourself enough to the point where you have confidence in you abilities. Then when it's time to take action, trust your training and go with the flow.
I can go on and on with many examples of over thinking, but I'd rather give you the chance to relate it to your personal life. So if you have a story about a time you thought too much and it ended up hurting you at the end, please share as our viewers would love to see that we all go through similar experiences.