There's an incredible documentary by director Damian Pettigrew called "Fellini: I'm A Born Liar" which literally retraces Fellini's footsteps through the unprecedented access he had to Fellini himself. The provocative title has more truth to it than you might think.
There's an excellent piece by Gaither Stewary from Counter Punch which dives deeply into Fellini's tricks with memory and it's impact on his work. You can read it here.