But "working hard at things that you love" isn't much of a challenge. Your motivation is already there, and your simply overcoming a lack of skills or knowledge.

What's difficult, and more common amongst mere mortals is twofold; trying to find motivation to overcome difficult things, and learning the skills and expertise to accomplish these things. Love for those things isn't really a factor.

Graham really is trying to simplify things a bit too much, and recycling the tropes of natural ability, practice and effort.