I think is so fitting that the man that created what is deemed as the most important american film also gave us a small personal film that is truly a masterpiece.
A creation based on the creation of others. Lies told as truth and truth told as lies. F for Fake is a documentary but not really. It is an illusion, but not really. There is truth here but also potent lies. It is a movie about forgery and a movie about the best forgery of all: film. It is a puzzle that does not need to be solved.
It is also a very personal reflection for Welles but also a grand statement about how potent lies can become potent truths (even tough they are not meant to last: but alas, isn't life just like that).