The Tang dynasty man of letters Yu Shinan once had a ju-i of rhinoceros horn which made him feel so good that he lost track of what he was working on, and he lamented: "It disrupts the rhythm of my writing."
唐朝文人虞世南就曾經用犀角如意抓癢，抓的舒服極了而忘了正事，不禁大嘆這如意：「妨吾聲律半工夫。」