There is an old story, told by James White, about a lighthouse keeper who worked on a rocky stretch of coastline. Once a month he would receive a new supply of oil to keep the light burning so that ships could safely sail near the rocky coast.
One night though, a woman from a nearby village came and begged him for some oil to keep her family warm. Another time a father asked for some to use in his lamp. Another man needed oil to lubricate a wheel. Since all the requests seemed legitimate, the lighthouse keeper tried to please everyone and grant all the requests. Toward the end of the month, he noticed his supply of oil was dangerously low. Soon it was gone, and one night the light on the lighthouse went out. Continue reading