台Taivo A Taiwan Mandarin dictionary

冰凍三尺，非一日之寒

bīngdòngsānchǐ,fēiyīrìzhīhán

ㄅㄧㄥㄉㄨㄥˋ ㄙㄢㄔˇ , ㄈㄟㄧㄖˋ ㄓㄏㄢˊ

Simplified 冰冻三尺，非一日之寒

1three feet of ice does not form in a single day (idiom); Rome wasn't built in a day

Keep 冰凍三尺，非一日之寒 and it comes back until you know it.