[dboreham]

After reading the relevant article section, I'd guess he's talking about the idea that problems can be mapped onto mathematical structures, allowing use of pre-known rules within said structure, for transformation and identity and so on, such that the problem can then be solved. He's saying that for simple problems if you're clever you can intuit the solution without that mapping/manipulation/solve process, but as a result you can never see how to solve more complex problems. Implication being that if you had been slightly less smart, you'd end up understanding mathematical structure earlier in life, with associated benefits in terms of success in certain fields. Like: https://en.wikipedia.org/wiki/Abstract_algebra