An anecdote from my father who helped 'slow' kids learn.
One time he dealt with a kid who struggled with maths. But he happened to know that this same child went to the horse races with his Dad and could calculate the pay-off from fairly complicated trifecta bets in his head.
Over and over my father found it was only motivation that was missing, not brain-power.
Fairly common story, buddies that were quitting school around 15 couldn't compute percentages, yet they did all kind of crazy calculation on the fly with their own non-regular currency unit system to sell drugs. I couldn't follow any of them.
More than motivation (indeed money is a strong one) they had a purpose and a concrete/tangible object to reason about. You can and will test your ideas otherwise you will experience failure. Nobody make mistakes twice when they sell.
Over and over my father found it was only motivation that was missing, not brain-power.