" Renounce and enjoy.” Those who are compulsively attached to the results of action cannot really enjoy what they do; they get downcast when things do not work out and cling more desperately when they do. So the Gita classifies the karma of attachment as pleasant at first, but “bitter as poison in the end” (18:38), because of the painful bondage of conditioning. Again, "

― Krishna-Dwaipayana Vyasa , The Bhagavad Gita