Just as one would never go into a marriage with the expectation of it leading down that bumpy road of divorce, the same applies to friendships. You go into friendship eager to forge what you hope will be a lifelong bond with that person upon whose shoulder you can lean, let down your guard and be as silly as any nonexistent law allows.
On our flight to England, I'd read Mark Doty's Still Life with Oysters and Lemon: On Objects and Intimacy. It is a book about still life pictures, but also about love, loss and our hunger for intimacy. The book moved me, and in the course of a ten hour journey, altered my understanding of why I travel, of why I need to travel.