Recognize the grump
Only one partner can be crazy at a time.
I know I don't have a great track record here, but I think she's right. In my (short) marriage, I always found that if it was her turn to be crazy, I could be sane and, in turn, get her to return to sanity.
But I never got a turn. Whenever I went loony, she took that as a cue to go loony, too.
I really think that in every relationship, both halves of the couple need to learn to recognize when it's the other person's turn. It's the only way to make it work. If you notice I'm being a big grump, you should recognize the grump and try to alleviate it instead of reacting.
Dontcha think?