Most sleepers can't understand the problems, powers and limitations mages have, and the mages find the lives of sleepers dreary and limited. From their perspective, most sleepers are truly asleep, unaware and unthinking pawns for greater forces. The mages can see through their shallow personalities to their inner cores, where their real power lies untapped. Nobody knows, not even the Masters. Most people are disturbed by such unbalanced people and won't listen to them.
Many mages also fear insanity, especially in the form of Quiet.
They have seen how Masters spend days quietly discussing philosophy with imagined people or fight their own hallucinations. They know that the line between madness and enlightenment is so fine, that it easily lost. Some mages try to control their own minds and perspective of the world rigorously, to prevent insanity from gaining foothold, but only succeed in avoiding enlightenment. The only way to ascend is to forget the notion that there is any difference between sanity and insanity. Another danger on the Path is the many philosophical and practical traps and pitfalls which exist for mages.