Um, all writers have to write a backstory in order to figure out where their characters will end up. Lying or not, he had to have written a backstory in oirder to organize things so well.
Bullshit. Tolkien literally made up "Lord of the Rings" as he went along, with only "The Hobbit" as backstory, which he wrote and published before that anyway. He made up "The Hobbit" as he went along too.