This is just my take on things - In seated meditation one doesn't actually experience the 'outers' one just recollects their existence.
Other people have thoughts/feelings/emotions = outer
You have thoughts/feelings/emotions = inner
You have a body (earth/fire/water/air) = inner
These elements exist outside of you = outer
There is no valid reason to consider that there is an I - it is all just bodies/feelings/thoughts/emotions.