1. Her hasty remarriage to his uncle, Claudius: Hamlet viewed their marriage as incestuous and disrespectful to the memory of his father, King Hamlet. He felt betrayed and disregarded by his mother's quick decision to marry her brother-in-law only two months after his father's death.
2. Claudius's ascension to the throne: As a result of their marriage, Claudius, Hamlet's uncle, inherited the throne of Denmark. Hamlet believed that his mother's actions facilitated Claudius's rise to power, usurping Hamlet's rightful place as the heir to the throne.
3. Lack of grief for King Hamlet: Hamlet was deeply affected by the sudden and mysterious death of his father, while his mother seemed to have mourned briefly before remarrying Claudius. Hamlet perceived her lack of prolonged mourning as a sign of disloyalty and disregard for his father's memory.
4. Guilt and shame: Hamlet's grief, sense of betrayal, and disgust at his mother's actions created intense feelings of guilt and shame within him. He felt conflicted between his love for his mother and his anger and disappointment in her.