In Really Good, Actually, the theme of expectations versus reality serves as a central thread, revealing the intricacies of human relationships and the journey of personal growth. Through the lens of the protagonist, Maggie, and a diverse cast of characters, Heisey adeptly explores the dissonance between individuals' anticipations and the often stark truths they encounter in their lives.

From the outset, Maggie grapples with the chasm between her expectations and the reality of her marriage to Jon. Initially, Maggie's expectations of marriage are modest; she seeks companionship and support in navigating life's decisions. She wants someone " to say all my stupid bullshit to or run my decisions past, someone to listen to me forever" (312). However, even these standards are too high when Maggie struggles to listen in return. Maggie states that marriage is "the only hallmark of what we think of as an 'adult life' that's still accessible" (235), and she initially believes that merely being in a marriage makes her an adult. In reality, Maggie is still too emotionally immature to take on the full range of responsibilities in a marriage, and although both partners contribute to the eventual break-up, Maggie soon realizes that her notions of adulthood and partnership are far from the reality she experiences.