Have you read Roland Barthes? If not, start with Camera Lucida, and you will love photography even more. It is a heavy piece of writing, but thankfully it is quite short.

It is dense, and it is impactful. It has so many timeless quotes about the "magical" philosophy of photography, and it was written when the medium was still in a juvenile phase.

As a result, it is a book about the wonders of photography, and the way we see, and frame photographs. How it captures history, and allows us to experience it, albeit being excluded from it (I am paraphrasing there).

It is an emotional book (for something about something so technical) and I try to read it at least once every two years. It keeps me motivated, it keeps me inspired, and it ensures I never lose the feeling of magic when I'm taking photos.