In December of 1995, Jean-Dominique Bauby, 43 year old editor in chief of Elle magazine in France, suffered a stroke which severely damaged his brain stem. After several weeks in a coma, he woke to find that he was one of the rare victims of a condition called "locked-in syndrome" or LIS, which had left his mind functioning but his body almost completely paralyzed. In a perverse sense he actually got fairly lucky because, unlike most victims, he was still able to move one eyelid. This allowed him to work out, with a speech therapist, a system of communication which entailed winking as someone slowly read through the alphabet. By using this code, he could painstakingly spell out words, sentences, paragraphs and, finally, this memoir.
The title of the book refers to the metaphors he uses to describe his situation. The physical paralysis leaves him feeling as if he was trapped within a diving bell, as if there is constant pressure pinning his body into immobility. However, at the same time, his mind remains as free as a butterfly and it's flights are as random. In fact, he calls the chapters of this book his "bedridden travel notes" and, indeed, they eloquently relate his journey through memory. [via]