Given that she kept the last chapter of her Harry Potter series locked in the attic for years, resisting all attempts to coax her into revealing its contents, it shouldn't surprise any of us that JK Rowling likes secrets.

What else were those stories based on, after all, but long-held mysteries that gradually came to light.

Being secretive is a bad habit, or so we're told as children, but in Rowling's case one can understand why she might have decided to write a novel under a false name, as if it was the work of a rookie writer. Hence her detective story, The Cuckoo's Calling, which was outed last week as being not by shadowy retired military man, Robert Galbraith, supposedly drawing on his earlier career for colour.

While I am not convinced questions were raised over Galbraith's identity because of his precocious knowledge of women's clothing, this apparently being what made some eagle-eyed reader suspicious – a hint from someone in the know seems far more probable – I do believe Rowling when she says she is disappointed the truth has come out so quickly. In light of the furore that greets each of her works, there must have been immense relief in being free of the media circus, and to let the book loose into the wild to have a life of its own.

She is not the first to try this trick. Some years ago, Doris Lessing sent out a manuscript of a novel, under the pseudonym of Jane Somers, to highlight the difficulty for first-time writers – even good ones – getting into print. Lessing's own publisher turned it down, but two more perspicacious publishing houses, in the UK and America, snapped it up, thereby no doubt pleasing and annoying Lessing in equal measure, her stunt having failed spectacularly but kept her literary ego intact.

Lessing's act took courage, and commitment. Had no-one taken her book, she would have lost precious time as well as money and face. Yet Rowling's move is admirable in its own way too, suggesting a writer for whom a novel and the way it's written still matters deeply. Her switch from children's books to adult fiction must have been pretty daunting, especially since, as a guaranteed money-spinner, she could not know if her publisher really thought the book any good, or was simply telling her it was because, no matter how pedestrian it might be, they knew it would fill their bank vault.

Even worse, she could not rely on the unavoidable tsunami of reviews to be fair. Few critics are scrupulously impartial when reviewing a Rowling novel. For some, to dismiss A Casual Vacancy as mediocre was to signal their highbrow literary credentials; for others, it would have seemed too cruel to do a hatchet job on the first title in this new phase of her career. Added to which, such is the race to be first into print with any comment on her works, reviewers would have had to read at breakneck and therefore unreliable speed.

What intrigues me most about Rowling's recent stunt is the insecurity it suggests. Taking a pseudonym hints at someone desperate for an honest response, to find out how she is rated when it's her writing alone, rather than her as a phenomenon, that is being critiqued. It's fascinating that, although established as one of the most successful writers of all time, she has felt the need to do this. It's like a secret millionaire living in a slum. She wasn't doing this to see what starting out was like for a beginner – she already knew that. She seems only to have wanted to throw her dice on to a level board and discover how she fared.

For her sake I wish the adventure had lasted for another book or two. With booksellers predicting The Cuckoo's Calling rocketing into the bestseller charts this summer, I wonder what she will take more pleasure in: the quiet critical praise it won when it was written by a nobody, or the extra cash she'll make now her fans know it's hers. I doubt there's any secret which she'd prefer.