The can't-tell-left-from-right thing is fascinating to me....I don't have it but people in my mom's family do.
I am curious about what it is, and have wondered:
Is it an isolated language issue ....for whatever reason the words "left" and "right" never get firmly glued to the spatial concepts? I have words like that, that I never learn permanently, but it doesn't affect my understanding of/concepts for the things they refer to.
Is a sort of abstraction issue....like left and right are concepts that only exist for you when you are looking at and comparing specific objects? Like your brain can't form an abstract spatial concept for them that you can think about without concrete visual references?
Is it a working memory issue? (to translate your left to someone else's left requires rapid perspective-shifting)
Is it different things for different people?
I don't know if it's more common for people with mixed-handedness, only that I have mixed-handedness and don't have any trouble with telling left from right.
_________________
"Coming back to where you started is not the same as never leaving." -- Terry Pratchett, A Hat Full of Sky
Love transcends all.