Once upon a time there was a house with a family of 5 living in it where the supply  of hot water was never quite enough for everyone in the house to have a comfortable shower in the evening, especially if all the long haired family members had all washed their hair on the same day. Try as he might the Daddy in the house could not make the hot water tank have more hot water without turning it on during the day when electricity was more expensive. 
One day the slightly dripping mixer tap in the kitchen suddenly started to drip with more intensity and the cold water that filled the small bowl in the sink filled a medium sized bowl. The Mummy in the house said when she was asked what she would like for a present for her birthday said that she would like a new tap for the kitchen, so that she could sleep through the night without an uncomfortable noise making her nights restless. Dutifully Daddy bought a shiny new silver mixer tap and it sat for a while on the kitchen table waiting for Daddy to have a spare moment to attach it to the sink.
Then one day Daddy woke up and the medium sized bowl in the sink that was always full of cold water was now a very large saucepan and was full of warm water. So Daddy decided that today was the day to change the tap. Being a curious sort of a chap Daddy opened up the old tap, after he had removed it, and took it apart to discover that all the wear inside the tap was on the hot side of the switch and none at all was on the cold side. 
Since the shiny silver tap has been living on top of the kitchen sink the family of five have yet to run out of hot water. And they all lived happily ever after.......

And with it some more children. It looks like the girls have crossed their legs for sunshine and then exploded babies all over the place as soon as we brought them home and put them back on lovely green grass. The second lambing has arrived sooner than anticipated. Spot the babies in photo No.3.