I don't know the specific significance without more information. It could be significant to those who know Billy personally, or it might have a broader meaning if it's a well - known story in a certain community.
Barefoot Billy in the 'barefoot billy true story' might be a unique individual. He could be a person who rejected the norms of wearing shoes. Maybe he had a philosophical reason for it, like believing that being barefoot kept him more in touch with the real world. Or perhaps he grew up in a situation where shoes were a luxury he couldn't afford, and over time, it became a part of his identity.
Yes, Billy the Kid was a real person. He was a notorious outlaw in the American Old West. His real name was Henry McCarty, and he was involved in various criminal activities, including cattle rustling and murder. His life and deeds have been the subject of many stories and legends.
Billy Elliot is based on a true story to a certain extent. It incorporates real elements but may have fictionalized parts to enhance the drama and entertainment value.