One possible theme could be loneliness. The rain man ghost might be a lonely figure, haunting a place because he has no one in the afterlife. Another theme could be vengeance. Maybe he was wronged in some way related to rain, like his property was flooded and he blames someone, so his ghost is seeking revenge.
I'm not really familiar with a specific 'the rain man ghost story'. It could be a very unique and perhaps regional or personal tale. Maybe it's about a ghostly figure associated with rain, like a spirit that appears during rainy days and has some sort of mystery or haunting related to it.
Well, 'rain man story' is a story that revolves around a unique individual. Raymond, in the story, is autistic but has amazing skills. For example, he can quickly count large numbers of objects just by looking at them. His brother Charlie discovers these abilities while on a journey with him. It's also about how society views and treats people like Raymond, who are different yet brilliant in their own ways.
One moral is about the value of family. Charlie initially sees Raymond as an inconvenience but comes to realize his importance and that family is more than just a blood connection. It's about acceptance and understanding of those who are different.
Well, to some extent. It takes elements from real stories and blends them to create a compelling narrative. But it's not a direct account of one specific true story.