Harry Potter and the Chamber of Secrets

I'm confused as to why they changed certain things in the movie. It's all little things, things that don't seem to make much difference, but it's like they felt the need to make some sort of change...

The books are still short enough that the movies aren't leaving much out. The writing is still far move juvenile than I remember - I think her writing improved as the books got deeper and more complicated. Practice, perhaps? Of maybe I'm even remembering the last book as better than it is!

The characters seem more true to the 'movie' versions now (other than a few physical details, like McGonnagal's glasses). It was much easier picturing the movie as I was reading, it seemed to mesh together better (I'm still not over how really unlikeable Hermoine was at the beginning of book one!).

So, onward to book three...