When Romeo is first introduced in the play, he is sulking because Rosalind does not return his love. He doesn’t keep it to himself and he is very dramatic about it: “Ay me! sad hours seem long!” (1.1.171)
Benvolio advises Romeo to forget Rosalind by “giving liberty unto thine eyes. Examine other beauties” (1.1.242-243). Romeo does not like his advice and swears that it will not work: “Thou canst not teach me to forget” (1.1.253).
We know that Romeo’s happiness and sense of self is dependent on love: “I have lost myself; I am not here: This is not Romeo, he’s some other where” (1.1.210-211).
Romeo suddenly forgets his misery as soon as he sees Juliet: “O, she doth teach the torches to burn bright!” (1.5.49). He quickly becomes obsessed and infatuated with Juliet, just as he did with Rosalind.