Toward the end of the first act, Madame Ranevsky remains overcome by emotion at being back in her childhood home. Drifting in and out of flashbacks in her dialogue, she apostrophizes her childhood and the cherry orchard. Although Madame Ranevsky seems to genuinely believe that nothing has changed, the audience finds her statements ironic, given that other characters have revealed that a great degree has changed since she was home last.
MADAME RANEVSKY [looking out into the garden]. Oh, my childhood, my pure and happy childhood! I used to sleep in this nursery. I used to look out from here into the garden. Happiness awoke with me every morning! and the orchard was just the same then as it is now; nothing is altered.
Throughout the first act, Madame Ranevsky and her brother Gayef participate in each other's childhood flashbacks. Exhilarated by her return to the estate and her reunion with her brother and other characters, Madame Ranevsky is only willing to recognize the extent to which things have remained the same—rather than the ways in which they have changed. Even if her comments are not marked by verbal irony, her self-delusion makes them seem ironic to the audience.
In fact, the play opens with immediate and overt signals about the changes that have taken place since Madame Ranevsky's childhood. In one of the first lines of the play, for example, Lopakhin reflects on his entrance into the bourgeoisie. He remembers that when he was fifteen and Madame Ranevsky was "still a slender young girl," she called him a "little peasant." Today he's a rich man. While his father was the serf of Madame Ranevsky's father, he is now in a position to buy the Ranevskys' estate from them. The change in Lopakhin's circumstances illustrates that the Russia of the play's setting has recently gone through significant socioeconomic changes. This sense of a new era looms in the background at all times, which makes the aristocratic Madame Ranevsky seem oblivious when she claims that "nothing is altered."
Additionally, Lopakhin is the bearer of bad news specifically as it relates to the cherry orchard, as he warns Madame Ranevsky and Gayef that it is "going to be sold to pay the mortgage." Madame Ranevsky hardly seems to hear what he says, answering his warnings with nostalgic outbursts about the glory of the past. She not only associates her childhood with the cherry orchard, but also associates the past with happiness. By calling her childhood "pure and happy," Madame Ranevsky implicitly identifies the present and future as corrupt and unhappy. At this point in the play, the praise Madame Ranevsky sings to the past is the only extent to which she acknowledges the bad shape her estate is in.