John Maxwell, in The 17 Indisputable Laws of Teamwork, writes:

During World War II, when Britain was experiencing its darkest days, the country had a difficult time keeping men in the coal mines. Many wanted to give up their dirty, thankless jobs in the dangerous mines to join the military service, which garnered much public praise and support. Yet their work in the mines was critical to the war. Without coal, the military and the people at home would be in trouble.

So prime minister [Winston Churchill] faced thousands of coal miners one day and told them of their importance to the war effort, how their role could make or break the goal of maintaining England's freedom. Churchill painted a picture of what it would be like when the war ended, the grand parade that would honor the people who fought the war. First would come the sailors of the navy, the people who continued the tradition of Trafalgar and the defeat of the Spanish Armada. Next would come the best and brightest of Britain, the pilots of the Royal Air Force, who fended off the German Lutwaffe. Following them would be the soldiers who fought at Dunkirk. Last of all would come the coal-dust-covered men in miners' caps.

Churchill indicated that someone from the crowd might say, "Where were they during the critical days of the struggle?" And the voices of thousands of men would respond, "We were in the earth with our faces to the coal." It's said that tears appeared in the eyes of the hardened men. And they returned to their inglorious work with steely resolve, having been reminded of the role they were playing in their country's noble goal of pursuing freedom for the Western World.