Tripitaka: Monkey, how far is it to the Western Heaven, the
abode of Buddha?
Wu-kong: You can walk from the time of your youth till the
time you grow old, and after that, till you become young
again; and even after going through such a cycle a thousand
times, you may still find it difficult to reach the place where
you want to go. But when you perceive, by the resoluteness of
your will, the Buddha-nature in all things, and when every one
of your thoughts goes back to that fountain in your memory,
that will be the time you arrive at Spirit Mountain.
— The Journey to the West