One day he asked me why the word breakfast was what it was. I was able to answer that one. It is the time you break the fast that you had been on all night. Interestingly, the word in Spanish has exactly the same meaning. Desayunar is the infinitive. Ayunar is to fast. Des would be the breaking, or not continuing the fast.
He then asked me about lunch. I had no answer to that. I told him I would ask the Podictionary host about doing an episode on it, and he did.
If you like words and their origins, Podictionary is a great podcast for you.