In all honesty?
I was never a Terry Pratchett fan. I never got into his particular brand of humor (Probably because I have a strange sense of humor).
But let's see here.
The man wrote forty Discworld novels. Forty. His total output was 70 books. I write pretty quickly. I don't write that quickly. He sold more than 85 million copies.
He wore a self-deprecating shirt to cons that became famous.
He collected carnivorous plants.
He had, of course, a turtle named after him, an extinct sea turtle named Psephophorus terrypratchetti.
Oh, and his response to being knighted for "services to literature" was that he got it for "refraining from trying to write any."
The speculative fiction community has a tightness to it. Even if you didn't know somebody and didn't read their work, each person sends out ripples and the degrees of separation aren't exactly small.
And finally, I'd note that Pratchett was apparently on particularly good terms with Death. So, I suspect he's doing just fine on the other side.