ㄨㄟˊㄉㄜˊㄅㄨˋㄓㄨㄥwéidé‑bùzhōng

为德不终
  1. 好事沒有到底為德不卒」。 拾金不昧報酬難免為德不終」。

to start on virtue but give up (idiom)​; to fail to carry things through, lack of sticking power, short attention span