Me neither, but this operational definition fits into his scheme of finding God. Enamored with Joy, Lewis sought to experience it as often as possible - in reading great books, listening to music, experiencing nature, etc, etc.
The book is valuable simply on the level of a biography and personal account history. In my generation basic math, reading, grammar skills, along with at least rudimentary knowledge of history, and social studies was "required" to pass from grade to grade and then graduate.) Aside from this however and on deeper levels the book deals with Lewis' rejection of all things spiritual, mystical, metaphysical or religious and decision to become an atheist. I could say a lot more about this book but I can't in this limited space give an account that would come close to doing it justice.
Lewis contends that these stabs of Joy are glimpses of the divine, and that they guided him inevitably to the Christian belief that characterized his later life. What's truly amazing about this book, to me, is how closely it follows my own life. Lewis followed up on this by investigating Norse mythology more closely, and subsequently stopped receiving stabs of Joy from it when it became an academic investigation isntead of something he did for pure pleasure.
-One of his favorite authors as a child (and adult) was George MacDonald. He was one of the very few Christian authors he read.
Most of the Sehnsucht took place while reading poetry or literature, and if not, it was because it transported him to the places in those stories. (Incidentally, this may explain why my generation seems to hate reading so much and why modern culture as a whole is striving to recover a love for reading in children.) I think Lewis hit upon it when he described myths as lies breathed through silver.
Early on in SURPRISED BY JOY, Lewis states that the best part of any biography is the stuff at the beginning, the stuff that deals with the subject in his or her youth. SURPRISED BY JOY doesn't really give us a glimpse into Lewis' professional life, and that was what disappointed me about it.
However this particular book sort of does not follow the two forms that that type of literature takes, which are: 1) I was a really, really, really bad person, but then God came along and now I am not; or 2) I became a Christian and this is how God has had an impact in my life. As I have suggested this book does not necessarily follow either of these forms because while it is closer to the first form, normally the writer of that style of testimony goes to great pains to emphasis how bad and evil they were so that the contrast of their current lives acts as evidence of God having worked in them (and the problem with that form is that the author tends to spend so much time emphasising their bad aspects, they have have little to no time to outline how God has changed them, as well as the statements about how they have changed being quite subjective, and as such need to rely upon other people as references to their changed life). After Lewis returns home from war the book, for some reason, seems to drift into some sort of esoteric form of writing as he outlines how he meets believers at Oxford (including Tolkien) and how he fights and riles against Christianity only to, in the end, reluctantly concede, at first, that there is a God, and then, as he begins to investigate spirituality, comes to accept that Christianity is the one religion that he can call authentic. What Lewis is suggesting (and what many other Christians also suggest) is that what God provides is that sense of joy and contentment that, well, may not be as intense and as strong as say ecstasy, but is a type and form of joy that gives one strength to continue.
He was a Fellow and Tutor in English Literature at Oxford University until 1954.