冰凍三尺,非一日之寒 [ㄅㄧㄥ ㄉㄨㄥˋ ㄙㄢ ㄔˇ , ㄈㄟ ㄧ ㄖˋ ㄓ ㄏㄢˊ; bing1 dong4 san1 chi3 , fei1 yi1 ri4 zhi1 han2] three feet of ice does not form in a single day (idiom); Rome wasn't built in a day ◄ ►