Why Are Rough Drafts So Hard?

After "His and Mine" was finished and sent along to be edited, and I was starting a new project for the first time in almost nine months, I realized something: rough drafts are really hard.
   I knew that already, of course...but, somehow, I had forgotten.
   And so, Gene Fowler's words had become true: "Writing is easy; all you do is sit staring at a blank sheet of paper until drops of blood form on your forehead".

I struggled for a while to figure out exactly what it was th...