What does "Primitive values do not share state with other primitive values" mean?

I suspect it's drawing a distinction between primitives and reference types - where in the latter case, two values (references) can both refer to the same object. If you have two primitive variables, there is nothing you can do to one that would affect the other.

It's not terribly clearly worded though, as even with reference types the values themselves (the references) don't share state; in particular, changing the value of one reference type variable doesn't change the value of another variable... it's the state of the object itself which is sort of shared "via" variables with the same value.