Mercutio has a partially negative way of thinking, but he is more rational than Romeo's impatient, love-seeking mind.
The comparison of the two characters shows Mercutio’s common sense as opposed to impractical Romeo. They are similar and different at the same time, but seeing them interact with eachother helps us better understand Romeo as a character when we see him compared to Mercutio. Romeo's role in the play is a young blind lover who in the beginning, doesn't believe that there could be another lady prettier than his Rosaline. Hs rejection of Benvolio's advice to find another love to replace Rosaline, shows Romeo's immaturity as a lover.
Similarly, Romeo claims to have fallen in love with Juliet (another girl) at the Capulet party. "Did my heart love till now?Forswear it, sight! For I ne'er saw true beauty till this night". When Romeo sees Juliet, he realizes just how impractical his love for Rosaline was. Mercutio on the other hand, is witty and anti-romantic. He sees love as only physical, like the nurse.
The way that he pursues love,highly contrasts with Romeo’s idea of romance. In Act I, Scene 4, when Romeo describes his love for Rosaline using the image of love as a rose with thorns, Mercutio mocks him by saying If love be rough with you, be rough with love;Prick love for pricking and you beat love down. His advice to Romeo is that if love is hard on you, be hard on love. If he fights back, he will figuratively knock love down. When Romeo says "I dreamed a dream to-night." (Act 1, Scene 4) Mercutio responds with his Queen Mab speech.
Queen Mab is described as a miniature creature that drives her chariot into the noses and into the brains of sleeping people to force them to experience dreams of wish. It clearly shows Mercutio’s imaginative and cynical side. He believes that dreams are only a result of the desires of sleeping people. Mercutio's speech indicates that because Romeo is so ignorant toward reality, he acts as a guide for Romeo.
