The image is deliberately revolting. A dog returning to its vomit is senseless and repulsive — yet the fool's return to folly is exactly as senseless and just as spiritually repulsive to God. Foolishness is not a single bad choice; it is the pattern of returning to what has already proven harmful. The New Testament quotes this verse (2 Peter 2:22) in describing those who return to sin after hearing the truth.
Memory phrase: Do not go back to wrong.
Talk about it: Why is it foolish to keep doing something you know is wrong?
Prayer: God, help me not go back to wrong things.