Pretty much anyone can work hard and adapt their performance if they understand where they are going wrong. However, identifying what needs to be fixed can be difficult. This has little to do with intelligence or even talent, I would argue, and a lot more to do with being one person, in one body.
Or, as writer Atul Gawande puts it in an excellent piece on the habits of top performers, it can be difficult to be our own "outside eyes and ears":
Élite performers, researchers say, must engage in "deliberate practice" – sustained, mindful efforts to develop the full range of abilities that success requires. You have to work at what you're not good at. In theory, people can do this themselves. But most people do not know where to start or how to proceed. Expertise, as the formula goes, requires going from unconscious incompetence to conscious incompetence to conscious competence and finally to unconscious competence. The coach provides the outside eyes and ears, and makes you aware of where you're falling short. This is tricky. Human beings resist exposure and critique; our brains are well defended. So coaches use a variety of approaches – showing what other, respected colleagues do, for instance, or reviewing videos of the subject's performance. The most common, however, is just conversation.
