Another possible theme could be sacrifice. In order to uphold the oath of love, the characters might have to sacrifice something, like their own personal desires or even relationships with other people. Also, the theme of commitment is likely present. The oath represents a strong commitment to the relationship and the person they love, which is a central aspect of the story.
Family might also be an important theme. The family background and relationships of the characters could play a role in shaping their personalities and influencing their love and life choices in the novel.
A third theme might be the pursuit of dreams. If one or both of the lovers had big dreams, like traveling the world or becoming an artist, their love would be intertwined with their individual pursuits. They might have to choose between love and their dreams or find a way to make both work in the context of their relationship.
One possible theme could be sacrifice. In 1941, during the war, lovers might have to sacrifice their time together, or one might sacrifice their safety for the other. Another theme could be hope. Despite the dark times of war, their love could be a source of hope for a better future.
One possible theme could be nostalgia. Since it's related to 1989, it might evoke a sense of longing for the past, especially for the time when the love story took place.
In a 2023 love story, the theme of second chances might be present. Maybe someone had a bad breakup in the past and in 2023, they meet someone new who gives them a chance to love again. Technology can also be a theme. People might have met through a dating app in 2023 and their relationship developed from there. And of course, the theme of family could be there. A couple in 2023 might be building a relationship with an eye towards starting a family in the future, so they are learning to support and care for each other like a family unit.
One possible theme could be social change. In 1950, society was evolving, and a love story might have been influenced by new social norms. Another theme could be sacrifice. The lovers may have had to sacrifice personal desires for each other or for their families.
Another theme could be hope. People in 1948 were looking forward to a better future after the destruction of the war. So the love between two people could represent the hope for a new start, both in their personal lives and in the broader context of the world around them. It could also be about the theme of change. 1948 was a year of significant change, and the love story could revolve around how the characters adapt to the new social, political and economic changes while falling in love.
One possible theme could be sacrifice. Given the historical context of 1917 which might involve war or social upheaval, the lovers may have to sacrifice their own desires for the greater good or for each other.
Another theme might be perseverance. The couple in the '1982 love story' could have faced various difficulties, such as differences in social status or family opposition. But they persevered in their love. And also, discovery could be a theme. As they got to know each other in 1982, they were constantly discovering new things about one another, which deepened their connection.
Another theme could be perseverance. Given the social norms and restrictions in 1820, the couple would need to persevere through difficulties to be together. For instance, they might have to fight against family - arranged marriages.