Brett and Daisy are shown to be unable to love in a sincere and authentic manner. Both women's ability to love is precluded by other elements. These realities have overshadowed the capacity to love in an genuine manner and demonstrate the result of failure to love in an authentic manner.
When Jake describes Brett as one who "can't go anywhere alone," it helps to illuminate why she embodies the results of the failure to love genuinely. Brett's fear of being alone precludes the selflessness required in love. She cannot generate the sense of sacrifice needed in love because her the need to avoid being alone takes over all else. It is for this reason that she moves from lover to love without ever really experiencing a full and actualized notion of love. The love that she experiences is one cast in the reality of a world where death and suffering can await anyone. For Brett, this sense of estrangement and alienation is met with an inability to thoroughly and selflessly love. In this reality, Brett experiences the results of a failure to love genuinely. Brett's inability to love stems from a fundamental insecurity. This condition highlights her failure to love genuinely. This prevents her from being able to fully embrace love and the commitment intrinsic to it. It also prevents her from being able to fully accept the selfless demands of true love.
This same inability to fully commit is evident in Daisy's characterization. Her waffling between both Tom and Gatsby reflects this. Daisy lacks the moral fiber to be able to effectively develop a relationship with either man. Rather, she embraces a lightness that enables to escape the reality of an emotional connection. She embraces the “well-forgotten dreams from age to age.” Her love of materialism might be the only element of her character that enables her to love genuinely. She weeps at the thought of the shirts being thrown because she knows that it will come to an end. The prospect of losing her material net of security prevents her from loving another in a genuine and sincere manner. Daisy cannot acknowledge the full commitment of Gatsby towards her because she is unable to embrace this herself. In her abandonment of Gatsby, she demonstrates the results of the failure to love genuinely.
For both women, the results of failing to love genuinely becomes evident in their lack of emotional connection to another. Brett and Daisy both embody a sense of freedom and dynamic energy. Yet, such vitality is without a grounded reality. As a result, both fail to love genuinely and are shown to be incapable of embracing the emotional quotient required to sustain a mature and committed relationship.