In the beginning of the play Romeo appears to be somewhat pretentious. He speaks dramatically of his "love" for Rosaline which, in fact, is probably not love at all. He speaks in rhyming couplets which makes his words sound insincere and rehearsed. He over dramatises the situation while talking to Benvolio (his cousin) which suggests that he is seeking sympathy or attention - such actions make him seem immature in comparison to the rational thinking characters in the play such as Paris.
Even when Romeo first sees Juliet his speech is artificial and again its rhyming couplets seem rehearsed. Romeo's sentiments only become more believable after he has met and decided he has definitely fallen in love with Juliet. However the fact that he developed feelings for her so quickly suggests again that he has a tendency to over dramatise. Furthermore, the speed at which he falls for Juliet seems only to reinforce the insincerity of his feelings for Rosaline, who seems forgotten after he meets Juliet.
In many ways Romeo's attitude to life is childlike and idealistic. Like a child he seeks attention and creates drama in the most unnecessary of situations. He seeks to seem mature by discussing love and the effect it has had on him but his actions have the opposite effect by making him seem childish.
Romeo does however have positive qualities too. He proves himself hugely loyal when he kills Tybalt in revenge for the death of Mercutio. Furthermore he proves his dedication to Juliet when he kills himself thinking she was dead. Both these actions could however be interpreted as out of proportion to the situation, again demonstrating Romeo's tendency to over-dramatise.