On movie theater food: If the various transcripts are reporting it right, which I assume is the case, then Munger's thoughts on why movie theater food costs much more than it does at other places. It's not because the cost is insignificant compared to the movie tickets or the movie theater experience. It's because the theater has its customers captive, not allowing outside food or drinks into the establishment. So they create for themselves a sort of "mini-monopoly" and for the 1.5 to 3 hours they have customers captive, they can charge outrageous sums for people to eat/drink. This is hardly a deep insight which is strange that Munger has it wrong.
For those that still disagree with me, let's assume that movie theaters changed their policies to allow food/drink from the outside in. That would significantly hurt their concession business. Maybe people would still get popcorn because there's no close substitute for that, but candy and soda could easily be brought in and few would choose to buy it at the concession stand at inflated prices. This would debunk Munger's thesis.