Hamlet is a character who is shown to be remarkably sensitive compared to the other characters around him. This is hardly surprising when we remember what he has endured in recent months with the death of his father, and the usurping of the crown that should be rightfully his by his uncle, followed by Claudius' marriage to Hamlet's mother. This experience is something that makes him incredibly introspective, far more than all other characters, and also makes him ask deep, philosophical questions about the meaning and value of life. Note for example how Hamlet refers to his life in his first soliloquy in Act I scene 2:
How weary, stale, flat and unprofitable
Seem to me all the uses of this world!
Fie on't, ah fie, fie! 'Tis an unweeded garden
That grows to seed; things rank and gross in nature
Possess it merely.
Note the metaphor of the "unweeded garden" that Hamlet uses to describe his view of the world. Again and again in his soliloquies Hamet shows a level of sensitivity and introspection that clearly separate him from other characters. In his famous "To be or not to be" speech we can see him debating the merits of life against death, for example, and we leave the play with the impression of a very intellectual individual trying desperately to make sense of the world that seems to be conspiring against him in so many ways. This is of course compounded by the way in which every character who he thought he could trust betrays him in some way, except for Horatio.