It seems the adults of Britain have a couple of guilty secrets. According to researchers, three-quarters of them read children’s books and a quarter indulge in romance novels.

The popularity of children’s books will come as no secret to anyone who’s had to commute in the summer over the past few years. Sometimes it feels that every other person sitting near you is engrossed in a copy of the latest Harry Potter, generally with the ‘children’s’ cover. As world sales have just topped a staggering 400 million (in 67 languages) for the series, it’s clear that it can’t just be children who’re reading them.

Pottermania shows no sign of abating – the paperback of Harry Potter and the Deathly Hallows will be released on July 10, so expect to see it on the train and by sun-loungers around the world. As part of the National Year of Reading, Waterstone’s commissioned 13 authors, including J. K. Rowling, to come up with short stories written onto postcards. A ‘prequel’ snippet featuring James Potter and Sirius Black raised £25,000, but you can read it now at http://www.waterstoneswys.com. In the first 20 hours the story was available on the net, some 70,000 people visited the site.

You’ll be in good company, too. Recently, Daniel Craig and Hugh Grant battled at a charity auction over an uncorrected proof of Harry Potter and the Philosopher’s Stone. Mr Grant stepped into the bidding at £11,000, but Mr Craig was eventually victorious at £18,000.

Also on the list of secret reads were Jilly Cooper’s novels and the Mills and Boon books. Don’t mock the latter – they’re addictive. I had a Scottish friend who loved a good M&B (or twelve) and I spent a washed-out Easter weekend with her stripping the mobile library bare of its stock (you’d be surprised how many you can read if you’re motivated). Founded a century ago, the company’s still going strong, especially online (http://www.millsandboon.co.uk), although things are rather more racy than they used to be.

So whatever you enjoy, keep on doing it (especially in this National Year of Reading) and don’t feel guilty. You aren’t alone.