Article.

Here's an excerpt of from an article entitled "The Church of Comedy" by David Dobkin - probably the best words I've read about comedy directing.  

10. YOU NEVER KNOW WHAT YOU HAVE UNTIL YOU ARE DONE EDITING

When you get to the edit and watch your assembly, you will want to cry. Almost nothing works. That’s because it’s not a movie yet. It’s an assembly. And the process you go through between that moment and a finished film is where you find out what you really have: the magic you’ve captured, and the magic you’ve missed."

I full heartily agree with David and can attest that it's exactly how I've felt at every rough cut viewing.  You feel that cold hard lump form in your throat as you watch your image for the first  time together - the lump repeatedly says 'this will never work', but yet you still persist.  And once the process is all finished you see the method in your madness and there's something in-front of you that, if nothing else, you learned from.