The point of his argument is that if it isn't obvious from code, there is usually an opportunity to make it obvious by rewriting the code. This is often not pra

The point of his argument is that if it isn't obvious from code, there is usually an opportunity to make it obvious by rewriting the code. This is often not practical, but it doesn't make it less true in the abstract. E.g., in your example one could make a constant for the 6% multiplier and call it LAST_DAY_OF_MONTH_DISCOUNT and take every possible other similar steps to have that idea of that comment embedded into the running code, not in the comments. This way everyone who reads the code can gain that deep knowledge by just reading it.