It is simple really, I don't know how magic works, so I can't see if they are doing anything wrong. All that I can judge by is whether or not the system is self consistent, using itself as a yardstick. Even so, I prefer more mechanistic and logical magic systems. Ars Magica is like a treasure to me, while I can live with D&D I prefer the fact that Ars Magica has a logical system behind its spells. Barring information to the contrary internal logic and consistency become the only means to judge. When these break down I lose interest.

On the other hand, I know that there is no optical mechanism in the eyes that would allow Cyclops to shoot laser beams. So it bothers me. Mind you, I enjoyed the first movie (have not seen the second), but I cannot bring myself to read the funny book.

The keys are logic and mystery. With that in mind I have less trouble with fantasy than bad SF. Bad mystery stories are the worst.

As a point of humor, the one time curiousity dragged me into a psychic fair I had a young woman drift up to me (yes, drift) and say 'you're a ceremonial magician, aren't you? I can tell by your aura!' and drift (yes, drift) off again. Mind you, if I was going to be any type of psychic, new age, or magical anything, ceremonial magician would be my choice... they have a logical magic system.

The Auld Grump

*EDIT* That said, I actually enjoy quite a few things. Internally consistent fantasy and science fiction is not uncommon in books, though rare in movies and television (B5 was a rare success). And it is rather the point of good mystery stories.