Pleasure is a sort of oblivion, a forgetfulness. Pain is remembrance, you cannot forget pain.
Osho, Rajneesh (Bhagwan Shree), Yoga Rabiya (Ma.), Ananda Vandana (Ma.), Prem Pankaja (Ma.) (1978). “The Discipline of Transcendence: Discourses on the Forty-two Sutras of Buddha”