Re: Dumb question
All the above are good explanations. I find when one is piling line that two common errors come into play. Provided line and rod are matched, fly line should behave if your casting arc and wrist positioning are correct.
Your flyrod tip should travel in a straight line at a slight downward angle, not in an arc. An arc will not allow proper fly rod loading (pile). Also, watch your rod wrist to ensure that you are providing the "path" for the rod tip.
I did a brief video on casting (roll casting) but it explains what I'm trying to say. Just search youtube, Duane Redford.