Two little girls playing with a ball in the garden. The ball rolls under a nearby bush. One of the little girls crawls under it to get it out. Unfortunately it's a thorn bush, so she gets a thorn stuck in her finger.
Crying, she runs indoors shouting "Mummy mummy, I've got a thorn in my finger - get some apple juice!"
Mum says: "But why do you want apple juice - wouldn't a bandage be nicer?"
The little girl says: "Well, I was playing with Rosie, and her big sister says that whenever she gets a prick in her hand she puts it in cider."