One of my recent must-reads is Bittersweet by Shauna Niequist. She chronicles a difficult stretch in her life where she learned "When life is sweet, say thank you and celebrate. And when life is bitter, say thank you and grow." This is one of the many thoughts she shares on friendship, real friendship, true friendship, deep friendship.
"Share your life with the people you love...don't let really intimate loving friendships become the last item on a long to-do list. Good friendships are like breakfast. You think you're too busy to eat breakfast, but then you find yourself exhausted and cranky halfway through the day, and discover that your attempt to save time totally backfired. In the same way, you can try to go it alone because you don't have time or because your house is too messy to have people over, or because making new friends is like the very worst parts of dating. But halfway through a hard day or a hard week, you'll realize in a flash that you're breathtakingly lonely, and that the Christmas cards aren't much company. Get up, make a phone call, buy a cheap ticket, open your front door. Because there really is nothing like good friends, like the sounds of their laughter and the tones of their voices and the things they teach us in the quietest, smallest moments."