painting behind the refrigerator

Today was one of those days as a teacher when it seemed to make more sense - logically - to simply not come to school.  I knew a week ago that I would not be teaching anything explicitly.  I had a speaker first period, and administrators had decided that the best use of third and fourth period would be watching navy seals jump out of an airplane onto our football field.  As a fellow teacher quipped, "I guess this must be this year's college fair?"

But as I weighed whether to take a day off, I thought back to last summer when I was completing a contract to paint a condo.  It was an open floorplan, and I was edging freehand, so by the time I had worked my way around to the kitchen, my arm was getting tired, my hand was cramping, and I began to wonder: do I paint behind the refrigerator?   It is in my best interest not to, and chances are that they never pull it out.  In any case, I certainly don't spend time painting well back there.   Why would I?

Obviously, this line of thinking is a slippery slope - why should anyone care about the quality of their work in general?  Particularly if it is not directly tied to financial incentive or career progression?  If the goal is not money, identity, power, or even productivity, why work?  Many of my fellow Christians had told me that work was merely a platform for evangelism - so why paint by yourself in an empty house?

Piper helps clarify below.  We work not so that other people might be inspired to give glory to God but to give glory to God ourselves, and as such, we should endeavor to present our fullest (albeit futile) effort.

"People make images of famous people to honor them.  God made man in His image so that He would be seen and enjoyed and honored through what man does."
~ John Piper, Don't Waste Your Life, p. 139