In "The Matrix," Trinity says, "Neo, no one has ever done anything like this." She speaks during the climactic rescue of Morpheus, when Neo performs an unprecedented assault inside the simulated world.
The line follows Neo's extraordinary decision to enter the heavily guarded government building rather than abandon Morpheus. Trinity recognizes that he is attempting something no human operative has successfully done before. Neo answers, "That's why it's going to work," capturing his growing confidence in his ability to bend the Matrix's rules.
Trinity is a hacker and a central member of Morpheus's crew, played by Carrie-Anne Moss. Her relationship with Neo develops from professional partnership into the film's emotional core, and her faith in him helps him move beyond the limitations he believes he has.
The quote is sometimes misremembered as belonging to Morpheus because he is the team's leader. In the scene, however, Trinity delivers the observation immediately before Neo's reply.