Why does Romeo choose to go to Capulet's party in Act I of Romeo and Juliet?

In Act I, Scene 1 of Shakespeare's Romeo and Juliet, Romeo is distraught over his unreciprocated love for Rosaline. He complains to his cousin Benvolio that she won't return his affection. The passion with which Romeo describes his feelings for Rosaline foreshadows his eventual love for Juliet. Benvolio is more level headed than his cousin and suggests that Romeo forget her and look at other girls. They discuss the problem:

Benvolio: Be ruled by...

In Act I, Scene 1 of Shakespeare's Romeo and Juliet, Romeo is distraught over his unreciprocated love for Rosaline. He complains to his cousin Benvolio that she won't return his affection. The passion with which Romeo describes his feelings for Rosaline foreshadows his eventual love for Juliet. Benvolio is more level headed than his cousin and suggests that Romeo forget her and look at other girls. They discuss the problem:

Benvolio: Be ruled by me. Forget to think of her.

Romeo: O, teach me how I should forget to think!

Benvolio: By giving liberty unto thine eyes.

Examine other beauties.

Basically, Benvolio is telling Romeo there are other fish in the sea and that he should move on. The perfect solution materializes as Capulet's servant comes upon Romeo and Benvolio in the streets. The servant has been charged with giving out invitations to Capulet's masked ball that very night. The servant, however, has a problem. He cannot read and so he asks Romeo to help him. While perusing the list, Romeo discovers the name of Rosaline. Benvolio urges Romeo to go the party and compare Rosaline to other girls of Verona. Benvolio seems confident that Romeo will see the error of his infatuation with Roslaline. Benvolio says,

At this same ancient feast of Capulet's
Sups the fair Rosaline whom thou so loves,
With all the admired beauties of Verona.
Go thither, and with unattainted eye
Compare her face with some that I shall show,
And I will make thee think thy swan a crow.

Of course, Benvolio is right. Romeo does go to the party and as soon as he sees Juliet across the room he is instantly in love and totally forgets Rosaline.