Wait. He is saying her demands are neverending and you advise him to keep a list of his failures to guess them ?

It’s not a list of failures, but a list of ideals, e.g. if she gets mad about tripping over your towel, you might write:

-always hang up towel after use

A relationship is like building a house, you can build one with out a ruler, but it will probably be more stable if you use a rule®.

These ideas/rules aren’t all equally important, but they provide a rule for straightening out or constructing a more stable house.

Note: this is related to a whole topic of life satisfaction and rules :)

Thanks for the clarification...but you qualifying her demands as "ideals" clearly shows you're taking one of them as being perfect and always-right and the other as needing to be re-educated. This is not a solid foundation for a relationship, to take your house metaphor.

A towel should not be left on the floor, anyone can agree, but on less obvious topics none of them can be credited as the unique source of Truth.

I should have noted that they are her ideals, not necessarily yours.

However if you strive to be her ideal man, it’s still worthwhile to know what those are :)