So.....the external world being the world outside of oneself?

Yes.
Outsides ones mind.

I make the distinction because we directly experiance the internal world.
We do not experiance the external world at all, we just experiance sense data that
may, or may not relate to the external world. We have no way of checking if it does
because we can not directly experiance the external world in any way.

The external and internal worlds are one and the same.

We view our world with ourselves being part of it, in effect, to stand outside of and observe oneself in order to analyze, comprehend, or allow our internal mind to encompass it and condense it into "reality".

Impossible!
If the internal world of out senses is the same as the external reality then colour
blindness is impossible and hallucinations or dreams are as equally real as everything
else. :doh:

What grounds do you have to claim that the external and internal worlds are one and
the same?

how can you perceive either if you're not a participant?