But one of the main themes of the play is that both Hamlet and Ophelia were untrue to themselves by being overly obedient to their fathers. Hamlet erased himself (and his love for Ophelia) from his own brain and wrote his fathers commandment there. Ophelia let her father tell her what to think.
http://www.thyorisons.com/#Envious_Sliver An Envious Sliver
I believe the main reason Hamlets age was specified as 30 was because he was born on the day his father won land from old Fortinbras 30 years before. I believe that 30-year interval was intended to parallel the 30-year interval from the death of Queen Mary until her widower (Prince Phillip of Spain) sent the Spanish Armada to recover England by by strong hand and terms compulsatory.
Source(s): http://www.thyorisons.com/ Be All My Sins Remembered Essays on Hamlet
Essays on motifs, symbolism,