Can you think too much? Very interesting question!
Actually there was an article in the Chicago Tribune a while back entitled "Thinking Too Much About Thinking Too Much." Well you can't answer this without thinking about it.... :-)
Well Einstein did not come up with his Theory of Relativity thinking the traditional logical manner but rather by leaving the problem and thinking of a trip he took on a train with his family. He then had sudden insight on the solution and then went back to work out the logical formula. His type of thinking was different but it was still thinking which resulted in the solution.
Imagine if we told Einstein, Shakespeare, and the Dali Lahma not to think so much! God knows we hope our politician would think more! The incredible number of people of all ages in our society who just do not think! How we could solve much of our society's ills if we could just get them to think more!
Then there is something to really be said for clearing one's mind to provide peace of mind. Meditation is quite a wonderful stress reducing method! One of my favorite Meditation sites: http://www.learningmeditation.com/ has a Meditation Room at the bottom & you can click to have some soothing music help you calm your mind!
So can you think too much? Perhaps one must look at the end product/result of the thinking at hand! Perhaps it is really one can think incorrectly. Could a balance of clearing one's mind and thinking more critically be the solution? What do you think? :-)