Ruth This one

“The disc, being flat, has no real horizon. Any adventurous sailor who got funny ideas from staring at eggs and oranges for too long and set out for the antipodes soon learned that the reason why distant ships sometimes looked as though they were disappearing over the edge of the world was that they were disappearing over the edge of the world.”
― Terry Pratchett, The Light Fantastic

“Why do you go away? So that you can come back. So that you can see the place you came from with new eyes and extra colors. And the people there see you differently, too. Coming back to where you started is not the same as never leaving.”
― Terry Pratchett, A Hat Full of Sky

“We're dealing here," said Vimes, "With a twisted mind."
"Oh, no! You think so?"
"Yes."
"But... no... you can't be right. Because Nobby was with us all the time."
"Not Nobby," said Vimes testily. "Whatever he might do to a dragon, I doubt if he'd make it explode. There's stranger people in this world than Corporal Nobbs, my lad."
Carrot's expression slid into a rictus of intrigued horror.
"Gosh," he said.”
― Terry Pratchett, Men at Arms: The Play

“You can't give her that!' she screamed. 'It's not safe!'
IT'S A SWORD, said the Hogfather. THEY'RE NOT MEANT TO BE SAFE.
'She's a child!' shouted Crumley.
IT'S EDUCATIONAL.
'What if she cuts herself?'
THAT WILL BE AN IMPORTANT LESSON.”
― Terry Pratchett, Hogfather