Perhaps the theme of acceptance is in the story. Loving someone in all their ways implies accepting them fully. It could also touch on the theme of sacrifice, where characters might have to give up something for the sake of their love. And the theme of perseverance in love, especially if there are challenges that the characters need to overcome in order to continue loving in all those different ways.
Love, of course, would be a major theme. It could also be about self - discovery within a relationship, as the characters might learn more about themselves while loving someone else.
Another theme could be perception. As we are dealing with two ways of considering time, the story might focus on how different people or characters perceive time. Some might see time as a precious resource, while others might see it as an endless cycle. This difference in perception can lead to various actions and decisions in the story.
A love story can change someone's social life. They may become more involved in their partner's social circle, which can expand their own network. This can bring new opportunities, like new job offers through connections made in the new social group, or just a more diverse group of friends to have different experiences with.
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 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.
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.
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.
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.
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 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.
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.