But there IS a clear point to the film - Several in fact. No one has said you have to go online to understand the film. Plenty of people understand it just fine without reading a thing about it. The discussions one can get into online can certainly make one's understanding of the film more robust, but Mulholland Drive isn't as obtuse as you are making it out to be.
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“It takes considerable knowledge just to realize the extent of your own ignorance.” ― Thomas Sowell