why he does that

Orwell could have ended the novel that way to challenge conventional storytelling or to force the readers to question certain ideas. Maybe he wanted to spark discussions and interpretations.

I think Salinger ended the novel that way to challenge conventional storytelling and force readers to think beyond the obvious. It might also be related to his personal style and the themes he wanted to convey throughout the book.

It could be that Chekhov wanted to create a certain impact or leave the readers with a lasting impression. Maybe it was his way of adding an element of surprise or mystery.

Maybe because novels are full of interesting stories.

He could be attracted to you. Your stories give him a chance to peek into your world, and he enjoys that. He may be looking for common interests or just likes seeing what you're up to.

Maybe he just doesn't have much experience in storytelling. He might not have read enough good stories to learn from or practiced enough to develop his own style.

Maybe he likes the feeling of love and passion that these novels portray.

He could enjoy the attention he gets when telling stories. People usually listen attentively when someone is telling a story, and he might like being the focus in such situations.

Maybe he's just interested in what you have to share.

Well, it could be that science fiction offers exciting adventures and imaginative concepts that he finds fascinating. Also, the exploration of future possibilities and advanced technologies can be very appealing.