Diabetics are (or become) very good at maths, even if they dont think so themselves. In the same way as, apparently, footballers (who, lets face it, aren’t top of the IQ tree) are very good at maths – because they know how to kick the ball and how hard to get it where they want it – they have no idea they are doing maths.
In fact, I think we need a new branch of mathematics – diabetimetry? Diabology? Diabetheory?