Peter Jackson, the visionary behind theLord of the Rings films of the early 2000s, remains rightfully proud of his work on the wildly popular fantasy series, but that doesn't mean he's nostalgic for all the effort it took to create the movies. The franchise made nearly $3 billion at the box office, and cemented Jackson as one of the few filmmakers skilled enough to adapt J. R. R. Tolkien's mammoth books. Needless to say, it was an "overwhelming" trek, and arguably the most difficult project Jackson's ever worked on.