There are all sorts of themes in love stories and I thought I'd look at a few of them in my posts.
First - Stories about someone who pursues a partner that society would frown on or maybe someone who falls for a person who's totally out of their reach. Master and servant scenarios, rich and poor, rival clans like Romeo and Juliet. This theme would fit with Pretty Woman or Jane Eyre. It's a common topic in Regency romances but I think less so in contemporary books, maybe because class differences have been eroded. No barrier now between royalty and commoner. The heir to the Swedish throne has married her gym trainer. Good for her.
Apparently - this has a psychological origin in the idea of women being treated dismissively by their fathers which makes them feel unworthy of love. But also it's a way of showing that even those who seem out of reach and out of touch can have tender sides. Not sure about those ideas but it seems to me that the idea of falling in love with someone you know you can't have is a common fantasy.
Hands up those who loved pop stars, movie stars, TV stars!! Much easier to love someone you can make perfect in your mind, someone you can pine over without fear of rejection because you'll never meet them. I had a plan to go to Hollywood, go on one of those tours, find out where X lived and then throw myself under the wheels of his car. Not to be badly injured but he'd take me into his house and well - fall in love with me. I never managed to save up enough money for the flight. Probably just as well or I might not be here today.
Two - Stories abourt sacrifice - where one person gives up life for love of another.