| Quote #1
[…] a social life which seemed nothing but a labyrinth of petty courses, a walled-in maze of small paths that led no whither, the outcome was sure to strike others as at once exaggeration and inconsistency. (1.3.13)
This is an important passage for thinking about "dissatisfaction" as well as "society and class." Dorothea's dissatisfaction, after all, stems from her social position. She feels hemmed in and hampered by social expectations and conventions. The only options that are available to her seem "petty" and pointless.
| Quote #2
But any one watching keenly the stealthy convergence of human lots, sees a slow preparation of effects from one life on another, which tells like a calculated irony on the indifference or the frozen stare with which we look at our unintroduced neighbour. Destiny stands by sarcastic with our dramatis personae folded in her hand. (1.11.2)
The narrator reflects on the development of important relationships between people: when you see someone for the first time, you have no idea whether they'll play an important role in your life, or not. You might feel "indifferen[t]" towards your "unintroduced neighbour" at first, only to find a few weeks or months or years down the line that they'll have a very important effect on your life. "Our dramatis personae" is the cast of characters in our own lives, which "Destiny" decides.
| Quote #3
[…] a few personages or families that stood with rock firmness amid all this fluctuation, were slowly presenting new aspects in spite of solidity, and altering with the double change of self and beholder. Municipal town and rural parish gradually made fresh threads of connection. (1.11.3)
Even though many families in Middlemarch (like the Vincys, for example) have been there for ages and seem to be as "solid" as a "rock," they actually change over time, too. Just because you've known someone since childhood doesn't mean that they won't be capable of surprising you as an adult. The narrator also introduces the metaphor of the "threads of connection" between people – this is important for the "web" that gets woven throughout the novel. All of the characters in Middlemarch are connected to each other through these "threads of connection" that form a giant social "web."