Many years ago, a guy named Joe worked in the coal mines. He would go to work early in the morning, go down the mine to the coal face and do his eight hour stint, then come back to the surface to get ready to come home. He followed this daily routine faithfully for years on end, down the mine in the morning and up at the end of his shift. Down then up, down then up. 

One day whilst he was at the coal face he swung his pick ax and the point went deep into a rock. He eventually managed to remove the pick ax from the rock, and as he did so he was engulfed in a deluge of water. He was absolutely drenched by the water, and his work mates remarked that he looked about 10 years younger since the water had covered him. They all tried to get soaked, and those that managed did indeed look 10 years younger. 

He, and those of his friends who had managed to get covered by the water, were thankful but they couldn't stop wondering why they had only been made to look 10 years younger. Why hadn't they been made to look 20 or 25 years younger than they really were? 

They finally figured that it was only a miner miracle.