reach down and get more when you feel there is nothing left

this seems to be the case when i am facing barriers with my research. it's tough. not only are the problems challenging, but you find yourself fighting other distractions and competitors for your attention/energy/time. however, whenever i feel discouraged or "tired in the 4th quarter" i have resolved (to myself of course) to remember how much i love challenges and to think about a life in which nothing was difficult. let's hope that works.