Spiritual intoxication...

"Why is photography, like the other arts, that kind of intoxication? And a quieter pleasure too, so that occasionally photographers discover tears in their eyes for the joy of seeing. I think it is because they've known a miracle. They've been given what they did not earn, and as is the way with unexpected gifts, the surprise carries an emotional blessing. When photographers get beyond copying the achievements of others, or just repeating their own accidental first successes, they learn that they do not know where in the world they will find pictures. Nobody does. Each photograph that works is a revelation to its supposed creator. Yes, photographers do position themselves to take advantage of good fortune, sensing for instance when to stop the car and walk, but this is only the beginning".

Robert Adams from the essay Colleagues