Terry Pratchett said this quote

“ I saved a man's life once,' said Granny. 'Special medicine, twice a day. Boiled water with a bit of berry juice in it. Told him I'd bought it from the dwarves. That's the biggest part of doct'rin, really. Most people'll get over things if they put their minds to it, you just have to give them an interest.'She patted Esk's hand as nicely as possible. 'You're a bit young for this,' she said, 'but as you grow older you'll find most people don't set foot outside their own heads much. ”