He's very stupid, because he fears someone may sneak into his house and steal stuff, he completely sealed up all the windows, so isn't doing like that the same as making big sacrifices to avoid minor troubles?
佢幾傻啊，爲咗怕人入嚟偷嘢，將啲窗口都封實晒，噉唔係等於斬腳趾避沙蟲？