Figure of speech where the latter part is surprising or unexpected?

For example: 1. Do not argue with an idiot. He will drag you down to his level and beat you with experience. 2. The last thing I want to do is hurt you. But it is still on my list. 3. Light travels faster than sound. This is why some people appear bright until you hear them speak. 4. If I agreed with you, we'd both be wrong. 5. We never really grow up, we only learn how to act in public. Thank you.