Animating dynamic text

Well, after many hours of tinkering and fist pounding, I have become enlightened! Still the question burns… why???

I found that when using dynamic text fields withing movie clips that were animated, FLash didnt allow me to apply any transitions to the text such as alpha fade or rotation (which would just plain kill the text altogether). That was until I tried creating the movie clip animation FIRST and then embedding a dynamic text field in it. Suddenly, I can dynamically load external text into my magical animations ala Swish!

Does anyone know why this process only works in this particular way?