是非 has two main uses: (1) right and wrong as an abstract concept - 分清是非, 明辨是非; (2) gossip, disputes, trouble - 搬弄是非 (stir up trouble), 惹是非 (invite trouble).
memory
是 (yes/right) + 非 (no/wrong) = the concept of right vs wrong, and by extension, the disputes that arise from disagreements.
