“Walk the talk”
I hate that abomination of a phrase. It’s “talk the talk, or walk the walk.” Most people born before 1980 know that.
Aristotle’s followers are said to have discussed philosophy while walking about with him—hence their name: “peripatetics.” I suppose they could have been said to “walk the talk.”
For the rest of us, the saying is “if you’re going to talk the talk, you’ve got to walk the walk”—a modern version of old sayings like “actions speak louder than words” and “practice what you preach.” Another early form of the expression was “walk it like you talk it.”
Many people now condense this to “walk the talk,” which makes a sort of sense (act on your speech), but strikes those who are more familiar with the original form as confused.