One of my pet linguistic peeves is the widespread misuse of the adjective proverbial. Consider a recent example, from a magazine profile of a government whistleblower: "When she grabs hold of something, she is like the proverbial dog with a bone in its teeth." Of course, this expression is not a proverb; it's a metaphor or simile. Or, less charitably, a cliche or bromide.
"Strike While The Irony Is Hot: Humorous Proverbs,"
Word Ways: Vol. 36
, Article 2.
Available at: http://digitalcommons.butler.edu/wordways/vol36/iss3/2