An elderly couple was rocking on the porch. The husband says: “I’m going to go get some ice cream at the store, do you want some?” To which the wife replied “Yes, get me some vanilla with strawberries. You’d better write it down, you know how forgetful you are.” “Hey, my memory’s no worse than yours!” “Okay.” Sometime later, husband comes home, gives wife a ham sandwich. Wife looks at it, says, “See, I knew you would forget – there’s no mustard on it!”