吃 ㄔ chī 一 ㄧ yī 堑 ㄑㄧㄢ ˋ qiàn ， 长 ㄓㄤ ˇ zhǎng 一 ㄧ yī 智 ㄓ ˋ zhì 吃 ㄔ chī 一 ㄧ yī 塹 ㄑㄧㄢ ˋ qiàn ， 長 ㄓㄤ ˇ zhǎng 一 ㄧ yī 智 ㄓ ˋ zhì Fall into the moat and you'll be wiser next time (idiom); One only learns from one's mistakes.