ㄐㄧㄤjiāngㄕㄢshānˋㄍㄞˇgǎiㄅㄣˇběnㄒㄧㄥˋxìngㄋㄢˊnánˊ

  1. 山河面貌年月變化稟賦性格根深蒂固比喻本性改變江山·秉性」、江山易改,稟性難移」、山河易改,本性難移

it is easier to change mountains and rivers than to alter one's character (idiom)​, you can't change who you are, Can the leopard change his spots?