The Truth by Terry Pratchett

"You can't handle The Truth."  Okay I got that out of my system. Now about the book. It was great. Pratchett delivered again. I'm sad that one day I'll have read the last diskworld by Pratchett. It reminds me of a concept I heard about while taking Japanese. It's the idea that something is sad because it is so beautiful. This one is about the invention of the printing press and the first reporters. What is the truth exactly?