It's sometimes easy to forget the work that goes into creating CGI effects, but then you peel back the veil and it becomes powerfully evident.
Remember when we talked about how Sir Ian McKellen couldn't take how effects-heavy The Hobbit was? Well, we may not actually have video of the classically trained thespian breaking down, but right at the outset of the video you can see why he would have. McKellen is so deft in his craft that you have no idea that he is, quite literally, having a conversation with himself.
In addition, it's cool to see just how many of those backgrounds weren't there, and nothing is more fun than a good creature feature. Plus, any day we get to see Andy Serkis playing Gollum is a good day indeed.
(via Comic Book Movie)