As a native speaker, for a very long time I didn't understand why "its" existed, and saw "it's" as parallel to "aredox's" - apostophe-s being either ownership o

As a native speaker, for a very long time I didn't understand why "its" existed, and saw "it's" as parallel to "aredox's" - apostophe-s being either ownership or contraction depending on context (made even more confusing because "s" without an apostrophe is pluralization with other words). Somehow it didn't click until late teens or early 20s that "its" is supposed to be a separate word along the lines of "his" and "hers".