The Hard Thing About Hard Things

In your opinion, is it easier to teach a technical non sales person how to sell or teach a salesperson how to sell a technical product? You know, I'd say the latter, and it depends, of course, on the complexity of your product. What's one great work of literature that you think every sales person should read? Ben Horowitz's book The Hard Thing About Hard Things. If you could change one thing about your business self, what would it be? I'd be like, I business self.