Seventy miles an hour

ANN:Look, Gary! That policeman's waving to you. He wants you to stop.
POLICEMAN:Where do you think you are? On a race track? You must have been driving at seventy miles an hour.
GARY:I can't have been.
POLICEMAN:I was doing eighty when I overtook you.
POLICEMAN:Didn't you see the speed limit?
GARY:I'm afraid I didn't, officer. I must have been dreaming.
ANN:He wasn't dreaming, officer. I was telling him to drive slowly.
GARY:That's why I didn't see the sign.
POLICEMAN:Let me see your driving licence.
POLICEMAN:I won't charge you this time. But you'd better not do it again!
GARY:Thank you. I'll certainly be more careful.
ANN:I told you to drive slowly, Gary.
GARY:You always tell me to drive slowly, darling.
ANN:Well, next time you'd better take my advice!