One movie I come back to time and again is 'The Hustler.' I don't think there's better dialogue in any film.
“When you make a decision, you need facts. If those facts are in your brain, they're at your fingertips. If they're all in Google somewhere, you may not make the right decision on the spur of the moment.”
“No one can persuade another to change. Each of us guards a gate of change that can only be opened from the inside. We cannot open the gate of another, either by argument or emotional appeal.”