Reading these, it’s neat to hear everyone’s headcanons! Glad I’m not the only one who likes to deduce “stories” based on what the villagers on my island say and do...
Mine is that Billy is an old man who likes to try and stay active in his later years. I got him as a starter, so I didn’t realize his house is supposed to be.. full of trash.. instead it looks more like a traditional Japanese style house. I think this is implied by the quote on his photo too, “Old dogs can learn new tricks”?
Also, he apparently likes to try out new fashions and especially loves to run around in his exercise tank, which looks exactly like a sports bra on him. (Not a headcanon, but the unexpected result of giving gifts to my starting villagers...) Naked Billy is now a permanent fixture of my island, if he goes to the void he will haunt other islands in his sports bra...