When Miss Brill heads goes on her weekly outing to the park, she happily sits there on a bench, watching the world around her. As she does so, she starts to construct little scenarios in her mind in which the people passing by are bit players. In Miss Brill's mind, the park is a gigantic stage on which she enacts her own plays using the other visitors to the park as actors.
In order to make her fantasies work, Miss Brill has to make sure that she doesn't let on that she's earwigging other people's conversations, which form the basis of the "script" of this real-life human drama. The last thing she wants is for the spell to be broken: for her fantasy to become real. Miss Brill has therefore had to become rather adept at listening in on what other people are saying without giving the impression that she's doing so.
She's been doing this for so long, she's become quite the expert. But, as she soon discovers to her horror, there are limits to her expertise. So long as she can control those...
(The entire section contains 3 answers and 606 words.)