Rather than being just a moment of nostalgia, Hamlet’s reflection on Yorick's skull becomes a profound meditation on mortality and his personal grappling with death. Seeing the jester's skull likely forces Hamlet to confront the inevitability and physicality of death, stripping away any romanticized or heroic notions about it. This could make him think of his father, whose death has left him shaken, and simultaneously heightens his own suicidal thoughts.

Yorick, who once represented joy and life to Hamlet, is now reduced to a skull, symbolizing the emptiness and finality of death. For Hamlet, this moment isn't just about Yorick; it's about the harsh reality that death reduces everyone, including his father, to dust. His famous contemplation of suicide in "To be or not to be" earlier in the play resurfaces, but now with a clearer image of death as something inevitable, impersonal, and ultimately leveling.

By viewing this moment through the lens of suicidal ideation, Hamlet's sense of futility becomes even more acute. Death no longer seems like an abstract philosophical question—Yorick’s skull makes it brutally real, forcing Hamlet to reflect on the meaningless cycle of life and the pointlessness of human endeavor, which feeds into his ongoing existential crisis.

"To what base uses we may return, Horatio!" (5.1.).

• Hamlet’s meditation on how even great men like Alexander the Great are reduced to dust and insignificance in death could deepen his existential despair. This realization of life’s futility might lead him to feel that if all efforts end in such base decay, then there’s little point in continuing to endure the pains of life.

"Alexander returneth into dust; the dust is earth; of earth we make loam; and why of that loam, whereto he was converted, might they not stop a beer-barrel?" (5.1.198-200).

• Hamlet’s grim reflection on how all men, no matter how great, end as dust used for mundane purposes deepens his sense of futility. If even a figure as powerful as Alexander is reduced to something so meaningless, this could heighten Hamlet’s desire to end his own life, as he may feel that continuing to live holds no greater significance.

OR (pick one theory because they use the same quotes, just different interpretations.)

Hamlet's encounter with Yorick’s skull could serve as a turning point where he begins to reconsider his suicidal thoughts. The crude, undeniable reality of death strips away any illusions of an escape or release that death might offer. Instead, it forces him to see death as something grim and final, perhaps even prompting him to realize that the suffering he faces in life is preferable to the absolute nothingness that death represents.

In this light, the "Alas, poor Yorick" speech isn't just a reflection on the end of life, but a moment where Hamlet gains a new clarity about the permanence of death. This could lead him to see his existential crisis in a different way, potentially motivating him to confront his problems—Claudius, his mother's betrayal, and his own inaction—rather than view death as a solution. Hamlet's growing awareness of life's fragility and death’s inevitable finality might be what ultimately leads him to reject suicide as an option, realizing that the unknowns of death could be worse than the trials of life.

"To what base uses we may return, Horatio! Why may not imagination trace the noble dust of Alexander, till he find it stopping a bung-hole?" (5.1.).

• Hamlet imagines even Alexander the Great reduced to insignificance, reflecting on how death strips away all dignity and meaning. This recognition may lead him to see that death is not an elevated solution to his suffering, but an equalizer that reduces all to nothingness, making him rethink his previous suicidal ideation.

"No, faith, not a jot; but to follow him thither with modesty enough, and likelihood to lead it: as thus; Alexander died, Alexander was buried, Alexander returneth into dust" (5.1).

• Here, Hamlet contemplates the inevitable fate of all humans, rich or poor, powerful or powerless. This reflection on death’s universality and its reduction of everyone to dust could suggest that Hamlet is moving toward an acceptance of life’s challenges, realizing that death holds no real answers.