【熟】【俗】【喻】【貶】吃屎吃到了豆子，比喻。①碰巧得到好處。畀佢食屎食著豆，執倒條好籌。（讓他碰上運氣，拈到個好鬮。）②沒本事的人碰巧做成了事。咁水皮都攞倒高分，系食屎食著豆嗻！（這麼差也拿到高分，是瞎貓捉到死老鼠罷了！）

(literally: to come across a bean whilst eating shit); an expression to describe when someone gets a windfall through sheer fluke / luck (with a disdainful connotation)