The "Stupid Question" thread reminded me of this.

Some years ago, California passed a law saying that if your windshield wipers were on, your headlights must be on also.

Shortly after the law was passed we were attending a NASCAR minor series event at Irwindale Speedway. In the midway there were all kinds of booths including one by the California Highway Patrol.

I walked up to one of the Patrolmen in the booth, saying, "I have a stupid question."
The CHP puffs up his chest and says, "Sir, there is no such thing as a stupid question."
I said, "California just passed a law saying that if the windshield wipers are on, the headlights must be on also."
CHP, "Yes sir, that is correct."
With a twinkle in my eye, I asked, "If the windshield wipers are on intermittently, should the headlights be on intermittently?"
CHP, after uncontrollable laughter, "You're right. that is a stupid question." followed by more laughter.