I can understand some people's frustration about this film and how they "don't get it". You need to be a Terry Gilliam fan, AND you MUST have a VIVID imagination. This is a fantasy film loaded with exceptional actors and very colorful characters. If you saw Time Bandits or Baron Munchausen, you will be more than pleased. If you are new to Terry's work, all I can say is go into this film with no expectations and a very open mind. Terry uses extensive imagery, simple dialogue delivered with full facial expressiveness and emotion!
What a great escape from reality and a very enjoyable film if you still know how to have fun and use your imagination. Leave reality at the door and step through the Dr.'s mirror. :-)