久病成良醫 [ㄐㄧㄡˇ ㄅㄧㄥˋ ㄔㄥˊ ㄌㄧㄤˊ ㄧ; jiu3 bing4 cheng2 liang2 yi1] long illness makes the patient into a good doctor (idiom) ◄ ►