Great Question
By Zen Master Seung Sahn, Extracted from "Compass of Zen"
  
Great Question means making the one-pointed mind continue, and continue, and continue, for a very long time. An example of having a Great Question is somebody who has not eaten anything for three days. They are very, very hungry. They cannot see the sky, cannot see the trees, cannot see anything. There is only one question filling their mind: "Where is food?" Or a man wanders in the desert for several days. The sun is beating down, and it's extremely hot! He is sweating heavily. His head is throbbing and pounding in waves. And all he wants is water. "Where is water? I must find water soon, or I will die." But this desert is very big, and there is no town nearby. The man is near death. So there is only one question in his mind: "Where is water?" He doesn't think about money, or sex, or fame, or sleep. He doesn't think about how nice his house is, or what kind of car he should buy. There is only one question filling his whole mind: "Where is water?"
  
Practicing with "What am I?" is called keeping a Great Question. We must practice with the mind of one who desperately needs even one cup of water to keep from dying. All our energy is completely focused on one point and doesn't move at all. A hungry person wants food. "Where is food?" And a thirsty person craves water. "Where can I find water?" If you truly want to attain your true nature, then simply keep the question "What am I?" Continue practicing with this mind, and enlightenment is not far away. But in Zen, unlike these situations, our Great Question does not want anything. "What am I?" Only don't know......