There is a huge protest outside the theatre where Tomas Wayne is watching the Charlie Chaplin movie. Despite the huge number of police, he manages to slip under the barricade, go downstairs, enter the building, find an usher uniform and make his way into the theatre, uninterrupted.
shareThe imagination theory is wrong because wayne and wife really did get shot in an alley after watching zorro.
shareI think it's fun speculating on how much of the film is in Arthur's head. But, in my opinion, he definitely slipped into that theatre. Too much of the plot revolves around it - it shatters his illusions of finding a father figure in Thomas Wayne. I don't think he imagines either patriarchal abandonment (Murray mocking him and Thomas rejecting him), which means he definitely got into that theatre.
For the most part, I feel like the events we see really happened, and then some of them have a greater or lesser degree of truth to presentation. So, who was mean to Arthur and how mean were they, for instance, would be "flavouring" he would add in his mind. That lady on the bus might've expressed concern for her kid or asked Arthur what he was doing, but did she really yell at him? In Arthur's head, for sure, and then we can debate or speculate on the Truth (I personally think she did respond aggressively - understandably, given the creeps that must ride that bus).