I don't disagree with anything in this comment, I was just pointing out that "deliberate practice" has several requirements, including practice being separate from execution, that makes it less usable, or even totally unusable, for some areas, such as decision making and choosing. The other main requirements are that it has a specific goal, should not be enjoyable and, as you pointed out, that is is challenging. Another thing, that is not part of the original requirements but is encompassed by them, is that you are not practicing when you are in "flow".