I am a 43-year old man who went to see this movie without any prior knowledge of the book or the plot. I purposely avoided any of the hype so I could enjoy the movie as a standalone product.
This was a mistake.
The story was painfully predictible, there were gaps in character development as well as logical flow and the visceral thrills were all dumbed down for the target audience (teenage girls). I mostly blame myself for this, not the movie, but I suspect this movie's intended audience will love it while someone who loves good movies will hate it.
If you are a grown man, save yourself some time and money, or give it to your teenage daughter so she can see the movie twice.