How on earth did 'with bells on' come to express enthusiasm? Why is good health compared to a small stringed instrument? ('As fit as a fiddle.') We all know what somebody means when they use these phrases due to our common knowledge of them, but it wouldn't be surprising if, when asked to explain them, you found that the cat had got your tongue, or you simply clammed up! "Spilling the Beans on the Cat's Pyjamas" provides us with the meanings to these well-worn and much-loved phrases by putting these linguistic quirks in context, and explaining how and why they were first used.