Worth a knighthood

Many English people feel that to call yourself Dr X unless your doctorate is in divinity or medicine is barely permissible, though in certain other countries if you can read you are probably Dr X and if you can also write you may well be called Professor X.
However, no-one would regard "Dr" as pretentious in the case of the most successful living author in the English language, for he is actually a shy man who likes to be known as Dave. His books have made him a multi-millionaire even though the income from film rights and merchandising has so far been negligible.
The first was written 45 years ago and sold 14 million copies in 22 languages; it is about to be followed by a sequel: The House Plant Expert Book Two.
Meanwhile, total sales of all his books, which set out clearly how to be The Rose Expert, The Flowering Shrub Expert, and so on, amount to 48 million copies; it is very pleasant to think that Dr D G Hessayon's sensible, useful books have far outsold J K Rowlings' childish fantasies and Dan Brown's silly drivel. Long may they continue to do so.
Oh, and Dave's PhD was from Leeds University, in soil studies.