"They got stoneder and stoneder and quit talking" reflects the idea of growing silence and disconnect among individuals who are increasingly absorbed in their own experiences. This line suggests a deepening introspection or withdrawal, perhaps highlighting the consequences of choices that lead to isolation. The phrase indicates a moment where communication fades, and the chaos of thought takes over, leaving individuals alone in their minds.

In Jonathan Lethem's "The Fortress of Solitude," this quote encapsulates a theme of solitude within a communal setting. It illustrates how, despite being surrounded by others, one can feel increasingly distant, as personal struggles and conflicts consume one's attention. The characters may be physically present but mentally disengaged, emphasizing the broader commentary on social relations and the effects of inner turmoil on connection with others.