Sometimes they respond, "whew, that's less than I thought. Go ahead." But the response that really annoys me: "Wait, but this is just really easy to do!" At this point, my response is usually "Well if it is so easy, why don't you do it?" That doesn't usually help things.
It is interesting when people self proclaim that they know nothing about computers, yet they know exactly how easy a programming problem is to do. Enough to contradict the programming expert. Oh well, I guess it's only a waste of about 10 minutes of my day.