This used to be me. I enjoyed pretty much everything I watched. I figured, since a lot of people put a ton of time, effort, and money into making a film, it must have at least some redeeming qualities. No one trusted my opinion on films because I "loved everything."
It wasn't until I watched a ton of movie reviews from various reviewers that I started to be able to tell the difference between a good film and a bad film. Now I'm pretty critical of films, and even made a review blog to discuss what I like and dislike about certain films.