The way to get through anything mentally painful is to take it a little at a time. The mind can't handle dealing with a massive iceberg of pain in front of it, but it can deal with short nuggets that will come to an end. So instead of thinking, Ugh, I've got twenty-four miles to go, focus on making it to the next telephone pole in the distance. Whether you're running twenty or one hundred and twenty miles at a time, the distance has to be tackled mentally and physically one mile at a time. The ability to compartmentalize pain into these small bite sizes is key.