What does it mean to "over-analyze" or "think too much?"?

Please provide examples.

People say this a lot, and my reaction is always, ‘how can you think too much?’ I mean, maybe people mean you don’t take action soon enough. But to say you think too much, it seems to me, is like saying you can understand too much. Why would you want to deliberately dumb yourself down, by thinking less than you do?

You can be wrong in your analysis. You can read into an analysis of a situation something that may not be there. I just don’t understand how you can think too much? Can anyone help me? Can you show me an example of thinking too much?