畳の上の水練たたみのうえのすいれん慣用句ことわざ未分類knowing the theory but being unable to put it into practicepractising swimming on a tatami mat
百日の説法屁一つひゃくにちのせっぽうへひとつ慣用句ことわざ未分類one blunder rendering a long period of effort uselessone fart in a hundred days of sermons