Jacques Hadamard gives an account of a similar phenomenon (a sudden flash of an idea) in Mathematics in his Psychology of invention in the Mathematical field (http://en.wikipedia.org/wiki/Jacques_Hadamard#On_creativity).

Also, very coincidentally, I have been reading up classical works on "proper conduct" in an attempt to do a spring cleaning of personal attitudes for pretty much the same reason as PG's - it just frees up a lot of mental energy. I'm currently doing a parallel reading of The Dhammapada and the Analects of Confucius. Earlier I read the Thirukkural (English translation, alas! - http://www.scribd.com/doc/20912297/Tirukkural-of-Tiruvalluva...).

If you or I rationally considered affairs and made up quotes ("'Tis easy to achieve an aim, if it be firmly kept in mind"), they wouldn't have the moral authority and rhetorical power they do coming from the world's classics. It just feels nice to work from ready-made axioms of conduct.