Stinking badges
Lessig has written books, fought court battles, and given talks that hinge on the idea that creativity always builds on the past. It makes for a good soundbite and anyone that's had an art class has probably agreed, but I don't know if most people buy the argument at its core.
While this is a somewhat silly example, the Stinking Badges Home Page shows you how far a throwaway line in an old book can go. It seems like a reoccurring joke in every western and cop show and it's still going strong.