I don't know how you managed to miss every single important thing about this film . . . that must be some sort of record.
I think the basic problem is that you're approaching it as a grownup . . . and you can't. It's not a grownup's movie and the books aren't for grownups or even for big kids - I would peg them at the 7-8 year old level. I first read them when I was 6.
I will say that, although you can enjoy the movie without the books, it helps to have read them first. I think (I can't really remember when I HADN'T read them.)
A bunch of my 17 y.o. daughter's friends went to see it together, and they were kind enough to let an old lady tag along. They all loved it to distraction - boys and girls between the ages of 15 and 18. One kid who is an exchange student from Croatia was a little bit puzzled about the other kids' very strong reactions to the film -- he thought it was pretty good but didn't understand why everyone was having such an emotional reaction (several of the girls were in tears, and I sniffled a little myself). All the other kids fell over themselves trying to explain, one girl summed it up pretty well I think: "This is our CHILDHOOD!" There's a nostalgia among teens (and grownups) who remember their moms and dads reading this book to them . . . sort of the same thing that drives some of the Winnie-the-Pooh mania. A FReeper whose name I can't remember pointed out that it's kind of like watching home movies -- if you know the folks involved it's a much more intense experience!
'Just Saw "Narnia"...it Sucked' I must have seen a different version. Too bad you missed the good one. It was GREAT.
"I don't know how you managed to miss every single important thing about this film..."
What important things are those?