> There is no guarantee in life that you will be handed success just because you showed some initial potential. That's what he wanted to be told hen he was young. Saying "Well done, you're very clever" is less helpful than saying "Well done, you worked hard for that. Keep working hard!" is better. When someone gets 85% but isn't working you can then say "Well done, but you can do better. You can work harder. You can be not just good, but great!".
Yes, as I've heard it stated before: there isn't enough emphasis being placed on the effort and the hard work that lead to success. There's plenty of praise being piled onto the child/person, and that's the problem. We say "Oh you're so smart because you got A's in your classes" instead of "Oh you worked so hard to get A's in your classes." One of those (the first) makes it sounds like your success is inevitable because you're smart, and smart people get things like A's in their classes. The other emphasizes a process of work, of gradual change through effort. Now, this isn't to say that no one should be told that they aren't smart. Many people are smart, and saying so should never be a bad thing. However, a more healthy mix of smart and hard work needs to be praised.