not really a paradox

It seems a paradoxical, not to say a perverse, truth, that one must work very hard just to stay in one place, the one place in this case, having the energy to work hard as a teacher.  I have to tire myself out (by getting exercise, whether through jogging or tennis) to not get too tired teaching, to maintain the momentum which I have acquired of keeping most of the students’ attention or at least politeness so far.  I have to work hard to be able to work hard.  Jesus says his yoke is easy–but there it is–that yoke!  The yoke is upon me-haha.