GAH! Why are middles so hard?

Does anybody else have that problem?
My first Fimfic, Something Magical This Way Comes, is progressing. I have the first draft of the start down, and I have the last quarter down on paper. But the middle two quarters, I can picture them, I know how I want them to go, but I just can't get it right on paper... A little frustrating really.
At least I got the cover art uploaded. I'm also learning to draw, I may have forgotten to mention that, so it's another draft. Need to learn inks next. Still, at least I'm actually doing this stuff now, been threatening myself with it for many years, so I figured it was about time I actually got on with it.
Nobody ever got anything done by sitting around, day dreaming.