"Angels do not dream," He said, when Michael was very young and the world was still a figment of His imagination, waiting to come into fruition. Michael doesn't question Him, because He is always right, but Michael doesn't know how else to explain it when his semblance of a mind wanders to strange, fantastic places - some familiar, some not.
Sometimes his mind wandered to very dark places, bringing him to his knees before the brother he unreservedly admired, his ultimate failure. He can still remember Lucifer's song, and he knows those tainted, bloodied hands that pluck the soft, white feathers off his battered wings.