My dearest, most faithful student Twilight,

Gaaaah, I'm tired. I don't think I'll raise the sun today. Here is a quick lesson why doing no work is important. Read carefully. I may use this in a test I assign you. Force equals mass times acceleration. If my acceleration is zero, and my mass is... I don't know. Thinking about it makes me feel fat. ANYWAYS, the force will equal zero. Work is equal to force times distance. If the force is zero, and the distance I've traveled is also zero (I'm still lying down in my bed, and won't be getting up anytime soon!), then the amount of work I have to do is ZERO! I know that you'll catch onto this lesson pretty quickly. However, the normal pony would not understand this intricate level of intelligence. So yeah, goodnight!

Yours truly,
Princess Celestia