I'm afraid I howled laughing when I recognised who William was partially based on. Said inspiration took years to admit that yes, maybe Pterry had sketched a lot based on his character.

Recognising one of the influences on Sacharissa was a lot more uncomfortable. Although I'm still proud of the spike joke.

Also, in classic Pratchett form, a vital plot McGuffin was possibly only created so an appalling pun could be perpetrated when it was released.