Confidence

I feel confident with a certain skill or body of information when I can feel the edges of that information - I know there is nothing missing and it makes a clear and coherent whole. That sense of completeness is essential.

I also feel confident with skills that you cannot do that with through peer review - I can tell I'm on a level with my peers and I have their good opinion.

I suppose both these approaches are about the pressures of competition - if you know you're going to win and can defend yourself, then it's all ok.

Harp played by ear was the first instrument I felt I could "get a handle on" - the first instrument I felt I could feel all the edges of. Such a relief.