I believe Tolkien answered someone's question about why Deagol had given Smeagol a gift, instead of the other way around, can't remember what it was, but you'll find it in the published Letters. Sorry I can't be more precise! It's a good letter, giving a lot of detail about how the Hobbit birthday-gift-giving works, starting with children giving their parents flowers on (the kids') birthdays. Have a good hunt!
