“One person ought to treat another person properly, even if the person's himself."
"What a strange idea!”
Mordion said.
Source: Hexwood (1993), pp. 181-182.
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Diana Wynne Jones 137
English children's fantasy writer 1934–2011Related quotes

“One person's craziness is another person's reality.”
Variant: One person's crazyness is another person's reality

“One person's weed is another person's wildflower.”
Source: An Unthymely Death and Other Garden Mysteries

As quoted in "Lincoln's Nuanced View of Slavery Explained By Renowned Historian" https://www.registercitizen.com/news/article/Lincoln-s-nuanced-view-of-slavery-explained-by-12077170.php, by Michelle Merlin, The Register Citizen (9 August 2012)
2010s

“Everybody should fear only one person, and that person should be himself.”
First lines.
The Riverworld series, The Magic Labyrinth (1980)