"In the fields only are the sours and bitters of Nature appreciated; just as the wood-chopper eats his meal in a sunny glade, in the middle of a winter day, with content, basks in a sunny ray there, and dreams of summer in a degree of cold which, experienced in a chamber, would make a student miserable. They who are at work abroad are not cold, but rather it is they who sit shivering in houses. As with temperatures, so with flavors; as with cold and heat, so with sour and sweet. This natural raciness, the sours and bitters which the diseased palate refuses, are the true condiments." - 'Wild Apples', Henry David Thoreau.