User blog comment:DancePowderer/Where There's Vinsmoke, There's Power/@comment-181.230.122.206-20160123000318

That could explain  why Sanji knows so much about history and other stuff...

I mean, for example, the knowledge he has about the Devil Fruits, like the names, and the "Book" of Devil Fruits he mentioned before... Maybe it's an encyclopedia of the Marines that no one outside of that business should be able to read...