People ask me if there are going to be stories of Harry Potter as an adult. Frankly, if I wanted to, I could keep writing stories until Harry is a senior citizen, but I don't know how many people would actually want to read about a 65 year old Harry still at Hogwarts playing bingo with Ron and Hermione.

If you love something - and there are things that I love - you do want more and more and more of it, but that's not the way to produce good work. So as an author, I need to write what I need to write.

However my parents - both of whom came from impoverished backgrounds and neither of whom had been to college, took the view that my overactive imagination was an amusing quirk that would never pay a mortgage or secure a pension.

Whether you come back by page or by the big screen, Hogwarts will always be there to welcome you home.

There appears to be something to do with vehicles and movement that stimulates my writing.