Buddha was asked one day by his disciples what he meant by ignorance. And he answered by describing how a person was once clinging in distress to the branch of a tree in the utter darkness of the night, not knowing whether there was earth or a ditch or water beneath him. All night long he trembled and wept and was clinging fast to that branch. And with the break of day he found he was not one foot away from the earth beneath his feet.