The scale of the Universe is simply astounding. The best way for the layperson to understand the distances we are dealing with is not to use words like Parsecs or light years, but rather to use easy to understand analogies.
"As he gazed around him the youth felt a flash of astonishment at the blue, pure sky and the sun gleaming on the trees and fields. It was surprising that Nature had gone tranquilly on with her golden process in the midst of so much devilment."
-Stephen Crane, The Red Badge of Courage