I have no problem remembering the rule, I absolutely recognize it immediately every time I see a misuse in someone else's writing. The problem is, my brain wan

I have no problem remembering the rule, I absolutely recognize it immediately every time I see a misuse in someone else's writing. The problem is, my brain wants to be able to do substitution of "<named-thing>'s" to "<it>'s", as if the pronoun were a variable and thus amenable to substitution wherever the name of the thing itself could be used, so without noticing it often comes out (after substitution) as "it's".