Where does he come up with these things

My wonderful mother-in-law took the kids for a few hours on Saturday night so I could join my family at a Dinner Theater. Zach has been working 7 days a week so he couldn't come. She told me this morning that when she was putting Samuel to bed he kept telling her that he didn't want her to leave him. She said that he had his monkey and kitty (his stuffed animals), so he had plenty of company. His response to this was "actually grandma, I need company that has bones." I don't know if I have every explained to him what bones are, but apparently somewhere along the way he picked it up.