What idea does the author develop regarding the impact of changing relationships on the individual in Romeo and Juliet?

When Romeo fell in love with Juliet, he began changing.
Before he met Juliet, the relationship he had with the Capulets was a troubled one. He
was constantly in a brawl with a Capulet. From the moment he met Juliet, he is changed
forever.

An example of this is found in Act III, Scene I.
Romeo has just married Juliet. Only an hour has passed and he meets Tybalt. Tybalt is
ready to fight Romeo. Romeo tries to convey to Tybalt that he does not want to fight. He
tells Tybalt that he loves him.

ROMEO

Tybalt,
the reason that I have to love thee
Doth much excuse the
appertaining rage
To such a greeting: villain am I
none;
Therefore farewell; I see thou know'st me
not.

TYBALT

Boy, this shall not
excuse the injuries
That thou hast done me; therefore turn
and draw.

ROMEO

I do protest, I
never injured thee,
But love thee better than thou canst
devise,
Till thou shalt know the reason of my
love:
And so, good Capulet,--which name I
tender
As dearly as my own,--be
satisfied.

Since Tybalt does
not know that Romeo has just married Juliet, he does not feel the same way as Romeo. In
fact he is ready to kill Romeo.

Tybalt kills Mercutio. Then
Romeo has to honor his friend's death by killing Tybalt. After all is said and done,
Romeo would not have killed Tybalt had not Tybalt killed
Mercutio.