Disappointment is a good sign of basic intelligence. It cannot be compared to anything else: it is so sharp, precise, obvious and direct… Disappointment is the best chariot to use on the path of the dharma. It does not confirm the existence of our ego and its dreams.
Trungpa revalues disappointment as the clearest indicator of awakening intelligence, arguing that it dismantles ego-accumulation and is therefore the most reliable vehicle for genuine spiritual progress.
, Cutting Through Spiritual Materialism, 1973thesis