Maybe they have a lot to share and want to make sure every detail is included.
Perhaps they have a rich imagination and find it hard to cut short the elaborate tales they have in their minds. Also, they might have a need to express themselves thoroughly and think the longer the story, the better.
It could be that he doesn't know his audience well. He might think that the things he finds interesting are universal, but in fact, they are not. For instance, if he is really into some very niche hobbies and only talks about those, it can be boring for others. Also, his storytelling skills might be lacking. Even if he has great stories, if he doesn't know how to present them in an engaging way, like lacking proper pacing or not using vivid language, the stories will come out boring.
Maybe they are bored and want to get attention. Telling crazy stories is a way to stand out.
It could be that he finds joy in captivating people's attention or he wants to pass on valuable lessons and experiences through his tales.
It could be that they have a pessimistic outlook or have faced many hardships that shape their narratives. Maybe they haven't found the positive in situations yet and focus on the sad parts.
It could be that they have a crush on you and want to keep up with what you're doing. Or perhaps they simply enjoy the type of stories you post and find them entertaining.
Some people constantly tell hilarious stories to make others laugh. It's a great way to create a positive and happy atmosphere around them.
Maybe he just wants to make us laugh. He enjoys seeing our happy faces when we hear those funny stories.
Maybe it's because that person's story is more popular or catches people's attention easily.
Maybe they just really love those stories and think they're worth sharing multiple times.
It could be that they have a limited number of experiences to draw from or they have a strong emotional connection to those particular stories. Also, sometimes people repeat stories because they think others haven't really listened or understood the first time.