Browsing at my local independent bookseller, I came across The Bloomsbury Group books and I bought 5 of the 6 they've published so far, including this book. Similar to the Virago books, these are republished out-of-print books, although not just by women. "A new library of books from the early twentieth century chosen by readers for readers."
Norman, a young man with a vivid imagination, is prone to making up wild stories "on the Spur of the Moment" whe he is in a tight spot. His father warns him that The Spur of the Moment can come back to bite you, but he can't help himself. One day, he and his friend Henry invent an older woman, Mrs Hargreaves. They keep adding more and more fanciful details about her while they're drinking in a pub, culminating in actually writing a letter to her imagined address. But when she arrives in the flesh on their doorstep, they get much, much more than they bargained for.
I found Miss Hargreaves to be a more likeable character than the essentially spineless and wishy-washy Norman. She's got a stout character and she's funny and although she can be overbearing and difficult, she does sense in some way that she's not like other people.
The only thing I didn't like about the book was that if Norman can change things just be making stuff up, why doesn't he? There are many ways in which he could easily fix all his problems. Why not just wish that Miss Hargreaves had a different personality or that she no longer doted on him? Instead, he wishes and does ever more ridiculous and complicated things that bring negative consequences on himself and his creation. In short, the author makes him rather unconvincingly stupid.
But I loved the premise and the writing was witty in that very British tradition of Saki, Jerome K. Jerome, and P.G. Wodehouse.