A formal assessment measures a sample of performance under specific conditions on one occasion. This is not a criticism. It does mean the result and the underlying competence are different quantities. Both errors occur. Somebody passes and car blog cannot perform reliably in ordinary conditions. Substance without the result. The frequency is high. Circumstances affect the outcome. The variables. Which is why repeating an assessment frequently produces a different result with no change in ability. The year following a formal assessment is generally where the real competence forms. Volume and variety. Which nobody assesses. Bad patterns establish alongside good ones. The absence of feedback is the mechanism. Which is the known weakness of a single assessment at the start. Some fields revisit. People judge their own competence poorly. Nothing internal detects it. Somebody watching. Which becomes unavailable after the formal stage for most people. The option exists. An hour with somebody who knows what they are looking at identifies things years of practice did not. Periodic revisiting. Memory outlasts capability. Not an endpoint. Anyone whose competence exceeded their qualification sought an outside view occasionally.