Hmmm, that's a toughie...
First off I learned that no style is an island and that if one truly wanted to be a well rounded MA one must study various specializations.
In regards to chi and "internal energy", I have learned ( at this stage anyways) that "co-ordinated energy" ie: total body mechanics, is one version of "chi" and I have learned that the bio-electical field all living creatures have is another.
Perhaps.
I was wrong about the value of grappling, and I was right.
I was wrong about Dim Mak, and I was right.
I was right about how crucial sparring and fighting are in the development of a fighter, BUT I was wrong in regards to how crucial that are in the continuing development of a MA.
Just to name a few...
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !