The Girl in Cabin 10 by Ruth Ware

I had never read anything by this very popular and respected author, so I gave this a shot. It was a great read: compelling, a "can't put it down" kinds of suspense novel. But the funny thing is, now that I am done with it (and I finished it a week or so ago), I can't remember the ending!  Not sure if that says something about ME or about the BOOK.
Probably about me.....
Sad.