One day when Margaret Thatcher was still the Prime Minister, she visited a mental institution to see how all the people were doing. When she was done visiting she phoned for a cab, but they were all busy. So she decided to phone home and get her husband to come and pick her up. She called the operator and asked to be connected to the Prime Minister's residence. The operator said that she couldn't do that. The Prime Minister asked, "Why not? Do you know who I am?" To which the operator replied, "No, but I know where you're calling from!"