Gopi Krishna's experience radically altered the path of his life. He came to believe that the human brain was evolving and that an individual's profound mystical experience was a foretaste of what would eventually become an all-pervasive transformation in human consciousness. By his own account, Gopi Krishna's initial experience triggered a transformative process that lasted for twelve years. During this time, the sensations of light, splendor and joy alternated with – and were often completely overshadowed by – sensations of fire, unbearable heat and bleak depression. In the introduction to Krishna's book, Frederic Spiegelberg writes: