*Romeo* believes he is "Fortune's fool" and that he has no control over his life. In fact, in 1.4 after explaining how going to the party will mean his death, he concludes by saying "But he that hath the steerage of my course/Direct my sail. On, lusty gentlemen!" and off he goes to what he already believes will be his death.
What Romeo says, however, is not necessarily what Shakespeare wants his audience to believe. We, as auditors of the play, need to evaluate action as well as words: what do these characters do, despite what they say?
And if you look at Romeo's behaviors (not to mention the behaviors of virtually every other character in the play including Friar Lawrence), you can see that he consistently makes choices in haste, without thinking-- choices that lead him to his death not because "Fate" willed it so but because Romeo's actions made it so.
I cannot think of a single place but one where Romeo ever attempts to forego impulsive and impetuous action, and that one place (3.1 when he at first attempts to stop the conflict between Tybalt and Mercutio) catapults him into a totally impulsive act: slaying Tybalt.