The first part of the quote, "Relationships last because two people make a choice to keep it," underscores the importance of commitment. Lasting relationships require a commitment to each other's well-being and happiness, even when faced with challenges.
The second part, "fight for it and work for it," emphasizes the effort required to maintain a healthy relationship. It acknowledges that conflicts and obstacles will arise, but it's the willingness to confront and overcome these hurdles together that strengthens the bond between two people.
In summary, the quote conveys that the key to a lasting relationship lies in the choices made by both individuals to commit, persevere, and put in the necessary effort to ensure its enduring and fulfilling nature.