I strikes me his understanding of gravity is on the same level as saying that everything attracts everything else, which is after all not much of a step up on saying that it's in the nature of water to be attracted to the moon - just a more general phrasing.

You can make more specific predictions if you know that everything attracts everything, and you know more about the laws of planetary motion and so on, and the gravitational constant and the decay rate and so on, but the basic knowledge of gravity by itself doesn't let you do those things. If your predictions after are the same as your predictions going in can you really claim to understand something better?

Seems to me you need to network ideas and start linking them up to data because you can really start to claim to understand stuff better.