Please explain Youth vs. Experience in Shakespeare's Romeo and Juliet.

The difference between youth and experience can best be seen by examining Romeo and Juliet next to their mentors Friar Laurence and the Nurse. When life gets tough and the kids are panicking, both adults step in to calm them down and speak reason to them. Romeo and Juliet cannot go to their parents for advice because of their families' feuding. Fortunately, the wisdom found in Friar Laurence and the Nurse help them through some difficult situations. For example, after Romeo kills Tybalt and is banished by the prince, he is panicking and unreasonable. Friar Laurence points out how childish Romeo is acting, as in the following passage:

"O, then I see that madmen have no ears" (III.iii.61).

"Hold thy desperate hand.

Art thou a man? Thy form cries out thou art.

Thy tears are womanish, thy wild acts denote

The unreasonable fury of a beast.

Unseemly woman in a seeming man" (III.iii.107-111).

By the way Friar Laurence has to speak to Romeo, it is evident how young and immature the boy is. If he thinks he is old enough to be married, he should be able to withstand the vicissitudes of life; so, this situation shows how young he really is. 

Next, while Romeo is panicking and crying over at the Friar's, Juliet is being told that she must marry Paris within a couple of days by her parents. She turns to her nurse asking for any word of joy. The Nurse breaks down the situation for Juliet by saying that Romeo is a great guy, but Paris is good too. The Nurse advises Juliet to marry Paris and let the first marriage go in order to satisfy everyone and not be thrown out by her father (III.iv.213-225). This seems like sound advice until Juliet decides suicide sounds better; thus, she heads to Friar Laurence for another option. 

Both Friar Laurence and the Nurse impart their wisdom and experience to the young lovers as best they can. Romeo and Juliet show their youth and inexperience when they are easily upset, threaten suicide, and must be coddled the whole time in order to solve conflicts. Unfortunately, none of them can fight Fate and no amount of youth or experience can stop the lovers' death.