I left the ending ambiguous, because that's the way life is. - Bernardo Bertolucci

"At a suburban barbecue one afternoon, a man slaps an unruly three-year-old boy. The boy is not his son."

(What a pitch, by the way.)

I finished The Slap last night. It's been a long time since I've read something this engrossing. The characters were juicy and beautifully flawed. The plot was simple, the subplots complex and thrilling. And the ending worked.

We always have a choice at the end of our book groups, and last night two of the six (!) books on offer* were lamented because of the dissatisfying endings. It's frustrating when you fall into a book, swim around for a dozen chapters, and find yourself wondering whether you missed something. We didn't choose either book. (Jamaica Inn by Daphne du Maurier won.)

Endings are tricky. They can't be too Hollywood, but can't leave you hanging. The ending of The Slap was perfect: just enough foreshadowing to have an idea of what happens next; a brief, shocking twist that made me yelp; a great ending line.

A Moveable Feast was not a hit with the girls. I chose it as an option because part of the ethos of our book group is to read books that we might not normally pick up, to explore genres and authors that are new to us. The safe choice would have been The Sun Also Rises, but I adore A Moveable Feast, so thought perhaps...

Two didn't finish because they loathed the man and the writing style and the name-dropping. Two thought it was a wonderful travelogue about a certain place in time. But most just didn't like the guy.

I wanted to protest, to read out the lines that I'd memorized years ago, like "You belong to me and all Paris belongs to me and I belong to this notebook and this pencil" or "When spring came, even the false spring, there were no problems except where to be happiest" or "To have come on all this new world of writing, with time to read in a city like Paris where there was a way of living well and working, no matter how poor you were, was like having a great treasure given to you." But the chat soon disintegrated, and I was left with a deeply dissatisfying ending.

It was good for me, to hear frank opinions about a book I put on a pedestal long ago.

My book group has improved my writing as much as, or perhaps more than, any book or course. They are my target market: women who read and make the effort to put life, families, partners on hold to talk about a book once a month. As a writer, you learn what works, what doesn't, what characters resonate, what subplots seem forced. My latest revision of Snakes was made with their voices in my head. I thank them for this.

*Our group immediately excludes books that are more than an inch thick. Last month I put The Lacuna and The Privileges up (both immediately eliminated), this month The Crimson Petal and the White was shunned. One woman said her husband will pick up a thick book, then look at the size of the print and decide, before reading a line. These are busy women, most with young kids. Thick books are too much of a commitment. Interesting. Take note, publishers.