Here is a beautiful post using spoon analogy for lupus:

I explained that the difference in being sick and being healthy is having to make choices or to consciously think about things when the rest of the world doesn’t have to. The healthy have the luxury of a life without choices, a gift most people take for granted.
Most people start the day with unlimited amount of possibilities, and energy to do whatever they desire, especially young people. For the most part, they do not need to worry about the effects of their actions. So for my explanation, I used spoons to convey this point. I wanted something for her to actually hold, for me to then take away, since most people who get sick feel a “loss” of a life they once knew. If I was in control of taking away the spoons, then she would know what it feels like to have someone or something else, in this case Lupus, being in control.

The excerpt does not do it a justice so make sure you read the full post.