Thinking about something is like picking up a stone when taking a walk, either while skipping rocks on the beach, for example, or looking for a way to shatter the glass doors of a museum. When you think about something, it adds a bit of weight to your walk, and as you think about more and more things you are liable to feel heavier and heavier, until you are so burdened you cannot take any further steps, and can only sit and stare at the gentle movements of the ocean waves or security guards, thinking too hard bout too many things to do anything else.