Andy telling Robert, “Farming ain’t your nature,” and Robert responding, “You’re wedded to the soil.” Although they don’t fully understand each other’s dreams, they support one another.

Ruth is the pivotal character who disrupts these dreams. She becomes enchanted by Robert’s romantic vision of the sea. When Robert confesses his love for her and his intention to leave, Ruth renounces her love for Andy and pleads with Robert to stay: “Please tell me you won’t go!” Ruth’s plea and Robert’s decision to stay set everyone’s lives on a tragic path, leading to the premature deaths of most characters and the potential downfall of Andy and Ruth. James foreshadows this when he warns that abandoning one’s true dreams leads to misfortune: “You’re runnin’ against your own nature, and you’re goin’ to be a’mighty sorry for it if you do.”

Responsibility
For both Robert and Andy, dreams come with responsibilities. Robert had committed to joining his uncle, Captain Scott, on a sea voyage. When he decides not to go, he shirks this responsibility, much to Captain Scott’s frustration. Scott says, “Ain’t I made all arrangements with the owners and stocked up with some special grub all on Robert’s account?” Meanwhile, Andy has been trained since childhood to manage the Mayo farm. When he abandons this responsibility, his father confronts him: “The farm is your’n as well as mine...and what you’re sayin’ you intend doin’ is just skulking out o’ your rightful responsibility.”

As the play unfolds, O’Neill illustrates other instances of neglected duties. Robert prefers indulging in books and daydreaming over working on the farm, a point Ruth highlights: ‘‘And besides, you’ve got your own work that’s got to be done. . . . Work you’ll never get done by reading books all the time.’’ Yet, Ruth is also guilty of shirking her responsibilities. She has an obligation to be a good mother to Mary but instead vents her anger on the child, roughly trying to make her take a nap and frightening her with threats of ‘‘good spankings.’’ This contrasts starkly with Robert’s gentle treatment of Mary, as depicted by the stage directions: ‘‘He gathers her up in his arms carefully and carries her into the bedroom. His voice can be heard faintly as he lulls the child to sleep.’’ Ultimately, Robert appeals to Andy’s sense of duty by expressing his dying wish for Andy to marry Ruth and care for her. Andy acknowledges he cannot ignore this request, noting to Ruth that he must keep his promise: ‘‘What? Lie to him now—when he’s dying?’’

Choices
Throughout the play, the characters face pivotal decisions. When Andy returns after three years at sea, he must choose between leaving again or staying at the Mayo farm. Staying seems logical since his primary reason for leaving—his love for Ruth—is no longer relevant. However, Andy tells Robert, ‘‘I’m certain now I never was in love.’’ He opts to go to Buenos Aires to speculate in grain rather than remain on the farm he once cherished. In the end, Robert remarks that this decision has made Andy the greatest failure: ‘‘You—a farmer—to gamble in a wheat pit with scraps of paper.’’ Robert’s choices also contribute to his misery. His most significant decision, which propels the play toward tragedy, is his choice to remain on the farm.

However, three years later, when Robert has the opportunity to change things during Andy’s return, he makes the disastrous decisions not to tell Andy about his failed marriage and to reject Andy’s offer of financial help. “No. You need that for your start in Buenos Aires,” Robert tells Andy. Although Andy tries to argue, Robert remains adamant. He also doesn't attempt to persuade Andy to stay. Ruth highlights this point angrily when she speaks to Andy: “And didn’t he try to stop you from going?” Robert’s pride in refusing both money and his brother’s help directly leads to his demise. If he had sought assistance from his wealthy brother sooner, Andy and Ruth could have moved Robert to a better climate, potentially saving his life. As Doctor Fawcett remarks, “That might have prolonged his life six months ago. (Andrew groans.) But now—. (He shrugs his shoulders significantly.)”

Happiness
The play also prompts the reader or viewer to question what truly brings happiness. Initially, everyone seems to be following their destined paths. Robert plans to go to sea, while Ruth is likely to marry Andy, who will take over the Mayo farm. However, when Robert, Ruth, and Andy stray from their intended paths, they all become unhappy. There is, however, some uncertainty about whether they would have found true happiness if they had stayed on their original courses. Although Ruth later claims she has always loved Andy, she initially professes love for Robert: “I don’t! I don’t love Andy! I don’t.” This starkly contrasts with her later statement to Robert, “I do love Andy. I do! I do! I always loved him.” This suggests that Ruth might not have been happy with either man. If Robert had gone to sea and Ruth had married Andy out of necessity rather than love, she might not have been any happier than she was with Robert. In other words, without marrying Robert and realizing he wasn’t the right one for her, she might never have understood that she loved Andy.

Similarly, there is some uncertainty about whether Robert would have truly found happiness at sea. Andy’s experiences in the Far East, which Robert has long fantasized about, are far from pleasant. Andy shares with Robert during his first visit home: "One walk down one of their filthy narrow streets with the tropic sun beating on it would sicken you for life with the ‘wonder and mystery’ you used to dream of." It remains unclear if Robert would have had a different experience.

Even the conclusion is ambiguous. Although Andy suggests that everything might turn out well in the end, Ruth’s despondent reaction leaves the audience questioning whether genuine happiness is attainable for these two characters: "She remains silent, gazing at him dully with the sad humility of exhaustion, her mind already sinking back into that spent calm beyond the further troubling of any hope."