How Kitty Got Her Brains Back

I am happy to say that somewhere between the denouement of THE PATCHWORK GIRL OF OZ, in which the pink brains of the Glass Cat are removed, and GLINDA OF OZ, which L. Frank Baum wrote on his deathbed, the Glass Cat apparently gets her pink brains back. Now, if wikipedia is telling me true, there are seven OZ books between THE PATCHWORK GIRL OF OZ and GLINDA OF OZ, so that means I have to read just seven more OZ books at the MOST to find out how and why the Glass Cat got back her pink brains, unless Baum just forgot, he was on his deathbed after all, so am I, a man almost 50 years of age, going to read seven more OZ books anyway? I can't say I won't.