Imagine you are a marathon runner, struggling at the half-way mark. You are fatigued, suffering from muscle cramps and out of breath. However, you are determined to complete the marathon and cross the finish line. So, what spurs you onto the finish the marathon despite the pain and fatigue?  I can imagine that one thought that would help is to know that the end is in sight and awareness that the pain and fatigue will eventually end. [caption id="attachment_72699" align="aligncenter" width="940"] Unlike marathon runners,...