"It's like a monkey at a typewriter" (Metaphor)
When Catherine is first talking to Hal about the fact that he's going through her father's notebooks, she tells him that her father's work is nonsense. She uses the metaphor of a "monkey at a typewriter" to signify just how nonsensical her father's work was at the end of his life.
"Watched him shuffling around like a ghost" (Simile)
This is another instance of Catherine describing her father's condition at the end of his life. She uses the simile that he shuffled around "like a ghost" to signify that Robert was barely conscious or aware of his surroundings at the end of his life, and his presence was hardly visible.
"They just pump the water out of Lake Michigan and bottle it" (Metaphor)
When discussing where to go for Catherine's birthday in the flashback of four years prior, Catherine says she wants to drink Chicago beer "with no flavor." Robert uses the metaphor that the people who bottle the beer just get the water out of Lake Michigan to illuminate just how bland and flavorless it is. Of course, this is not the literal distillation process, but it is a vivid illustration of the beer's flavorlessness.
"Someone turned a LIGHT on in my head" (Metaphor)
When Robert experiences his supposed epiphany around his own work in the flashback from three and a half years earlier, he excitedly tells Catherine that he's stumbled upon some inspiration. He uses lofty metaphors to describe this inspiration, telling Catherine that "someone turned a light on" in his head. This is obviously a metaphorical representation of what it feels like for him to feel like he's stumbled on some innovative ideas.
"It's a geyser and I'm shooting right up into the air on top of it" (Metaphor)
This is another metaphor that Robert uses to describe the sensation of suddenly having inspiration. He describes the feeling as being like sitting on top of a geyser that is bursting upwards, something external that is happening to him, rather than something he is doing himself.
