with the book, when things happen, when someone says something, or does something, or feels something, or thinks something, you can stop, let the words wash over you, absorb what they could possibly mean, how it could apply to you personally, how you can identify with it. in the movie, your engagement with the plot forces you to move with the flow, there is no time for thought, for reflection, for you to ponder, how did lucy feel, what did aslan mean, no time, no time at all - just plenty of happenings, happenings, happenings, not much space, not much time, for introspection.
of course, all this could always be done after - but chances are, the ghost of the thought that had first occured upon the play-out of a particular event during the movie would long have fled. you don't wanna watch it a second time in just the bid to recall it from the recesses of your mind, why, because a second, third time could eventually desensitise you; it no longer means that much, it is no longer able to strike you with such intensity, even if you do recall, it'd prolly be vague, you might never be sure that was quite what had initially come to you.
even so, the movie does have its merits (afterall, it did cause me to reflect); but really, nothing beats the reading experience. just as the kids had left narnia for so long that they had almost clean forgotten its reality, i have almost completely left behind all that narnia and aslan had once meant to me. it is after all children's fiction. but no, it is so much more than just that to me, and i'm sure this is exactly what c.s. lewis meant for the chronicles to be - more than just that.
i will pick them up again.