@futurebird I know it has nada to do with Pratchett but I love this quote from Jane Yolen re: similarities between her Wizard's Hall and Mr. Potter (such an excellent humble dig):

(From wikipedia)
Regarding the similarities between her 1991 novel Wizard's Hall and the Harry Potter series, Yolen has commented:

I'm pretty sure [J. K. Rowling] never read my book. We were both using fantasy tropes—the wizard school, the pictures on the wall that move. I happen to have a hero whose name was Henry, not Harry. He also had a red-headed best friend and a girl who was also his best friend—though my girl was black, not white. And there was a wicked wizard who was trying to destroy the school, who was once a teacher at the school. But those are all fantasy tropes ...There's even a book that came out way before hers where children go off to a witch school or a wizard school by going on a mysterious train that no one else can see except the kids, at a major British train station—I don’t know if it was Victoria Station or King's Cross. These things are out there ...This is not new.