Right, and for pronouns you don't just put apostrophe s after. So you don't make "it" possessive by adding apostrophe s just like you don't add apostrophe s to "he" or "him" to make it possessive.
If you treat the pronoun "it" like a regular (non-pronoun) noun instead of like other pronouns, that is itself an exception.
That's me on my first DS1 playthrough when I didn't understand bonfire kindling so I kept restarting at the first Anor Londo bonfire for the O&S fight so I could get 5 extra flasks only to get wrecked over and over anyway.