Another life

Reading The Bride Stripped Bare recently, I was in turns stunned, awed and appalled by the surprising secret life of what everyone considers a stay-at-home wife. The novel, which was criticised as literary porn, is "basically a very honest take on sex, from a woman's perspective," says the author Nikki Gemmel, who first published the book anonymously in 2003.
That aspect aside, what I was most taken by was the protagonist's secret life, her musings, her lies, her joys, her smiles, tears, jealousies and more... all running parallel to the other, seemingly regular life she leads. And it's not like her regular life is insipid or meaningless: it's filled to the brim with its own moments of fun, joy, grief and all that... Reading the book, I wondered if many of us do the same: smile at one person and think of another, scream at one for another's faults, love one even as you live (quite happily even) with another!
Even if most of us do not go to that extent, most of us do have a secret life that only we know about. It may just be a closet crush, a deep fantasy or a even unpublished scribbles that you may not have showed even your closest friends.
The novel intrigued me, to say the least... What do yo think? Is a secret life the norm? Or is it a devious deviation?