Your phrase likely refers to the popular non-fiction book by Gurcharan Das . Key Themes of the Book

If you were referring to a different type of "good piece" (like music or games):

: Das distinguishes between feeling bad about an outcome (regret) and truly feeling the suffering caused to others (remorse). Other Potential Interpretations

: In piano pedagogy, a "good piece" is often one that matches your current skill level—technically challenging but achievable with consistent practice.