Pratchett held a keen understanding of academia, as well as of politics, policing, law, assassination, and another myriad subjects that his background wouldn't suggest he was properly educated to address. Clearly the man Terry Pratchett was insufficiently educated to produce such brilliant witty novels. He was no doubt a front for some other writer who had an extensive advanced education in various specialties. It's the only reasonable explanation.
Hmmm. I wonder if I can get a grant to research the possibility?
Story available online.