The Mystery of Wei Zi

Its "mouth" "right" has a mouth, and "left" has no mouth; "Cool" has a mouth, "hot" has no mouth; "Cry" has a mouth, "laugh" has no mouth; "Life" has a mouth, and "death" has no mouth; "Jump" has a mouth, "walk" has no mouth; "Tall" has a mouth, while "short" has no mouth; "Wisdom" has a mouth, "Fool" has no mouth;