\section{Prologue to Longing} \lettrine{I}{n} this book, we will mostly consider human longing. But first let's consider how Longing may be woven into the very fabric of the Cosmos itself. Metaphorically speaking, after the Big Bang, the Cosmos could have been ``content'' to remain an amorphous cloud of gas. But it didn't. You're here, reading this text, because it didn't. This is quite strange. \medskip In the chapter that follows, we consider Longing from a cosmic perspective. For me, perhaps the biggest challenge writing it was trying to wrap my mind around the time frames involved. In our culture we're trained to time frames of corporate quarters and two-year election cycles. But the time frames of the Cosmos and Life within it are millions and billions of years. Then we'll narrow our focus to Longing in mythology, some lives gripped by Longing, then Longing in each of us personally. We conclude the book by bringing it full circle with a story about Longing greater than the Cosmos itself\ldots