Personally, it's the double learning curve of having to learn Lisp and Emacs. I understand the basic concepts of Lisp now, but could someone point me to a good introduction to learning Emacs, Slime, and Lisp all at once? Does Practical Common Lisp do that as well?
I don't think it has to be true, though they do go together well. Not all CL hackers use Emacs. You might consider trying the Lispworks IDE, or the Allegro IDE (on Windows) or the Clozure IDE (on Mac).
There are certain things that usually just come with practice, emacs and slime usually seem to fit in that category. Once you have gone through the tutorial most of the time you just look up things or figure them out until you remember what to do in a specific situation.
There probably are some screencasts for introduction to emacs, slime might have some available as well.