When once a dog has taken to gnawing your shoes, you can never break him of the habit.
οὐδὲ γὰρ κύων ἅπαξ παύσαιτ᾿ ἂν σκυτοφαγεῖν μαθοῦσα.
Original text (Ancient Greek)
More quotes by Lucian
Ignorance is a dreadful thing and has caused no end of damage to the human race.
The effort only shifted me from the frying-pan into the fire.
Attribution
Quote text and notes from Wikiquote: Lucian (page history), available under CC BY-SA 4.0. Source quality and labels are our own summary of what Wikiquote records.