The speaker in the poem does not define success or failure in love through conventional means. It is the opportunity to revel in one "last ride together" that drives the speaker. Whether one takes this literally as a ride, symbolically as a last opportunity to be with one another, or sexually, it is in this particular instant where success is evident and where "eternity" is made. One might suggest that the speaker has failed in love. Yet, the speaker's metric for success is that he has been able to establish one last shared experience with the object of his love.
The acceptance of the mistress for one last ride is where the speaker finds success. This mere experience moves him to a feeling of transcendence, beyond traditional metrics of success and failure: "I and my mistress/ side by side/ shall be together, breath and ride, / so one day more am I deified/ Who knows but the world may end to- night?" The speaker revels in the moment. It might be a consolation. Yet, the speaker believes that this moment is what transcends the traditional understanding of "success" and "failure." The speaker addresses this later in the poem: "Fail I alone, in words and deeds?/ Why, all men strive and who succeeds?" The speaker is open about the fact that failure and success are external constructs, determined by a measurement that exists outside the subjective. Yet, the speaker is convinced that this love resides in his own sense of identity. The act of riding together one last time is about his love. It is not defined as anything else. Since it is his, there is no need to console himself about the issue of failure. His love is his to possess. It's not anyone else's right, including hers, to determine success or failure.
This affirmation of the subjective is continued throughout the poem. The ride itself defines success, a condition of transcendence within the mind of the individual: "We rode; it seem'd my spirit flew,/Saw other regions, cities new,/As the world rush'd by on either side./I thought,--All labour, yet no less/ Bear up beneath their unsuccess./Look at the end of work, contrast/ The petty done, the undone vast,/ This present of theirs with the hopeful past!/ I hoped she would love me; here we ride." The speaker equates the experience of the ride as moving beyond "success" or "failure." The speaker would view such terms as temporal. What the speaker is able to experience with a "spirit" that "flew" and seeing "cities new," is something transcendent. This experience that goes beyond "unsuccess" associated with "labor" is where the speaker affirms his own subjectivity. There is no need to suggest consolation in the face of such a transformation. In this light, the speaker would suggest that the "instant made eternity." This is something beyond "success" and "failure." Upon the conclusion of the poem, the speaker has gone past that which is "failure" and even the need to be consoled because of it.
Browning once wrote, "Take away love and our earth is a tomb." This affirmation of the experience in love is one that revels in the instant. The experience of love is one where instant and eternity converge. For the speaker of the poem, being able to experience one last ride together is where success lies. It permanently enshrines love in the speaker's mind, able to live forever, and "Ride, ride together, for ever ride". This is where the speaker turns in the face of external judgments regarding failure.