I have a fond memory of a flat mate of mine helping me with some computer problems I was having, he was studying computer science at the time and I asked him a question about how it works. Not feeling like explaining the complex details knowing that I wouldn't get it anyway, he simple said "it's magic Jory".
This I fear is the general attitude towards the concept of chi, the people of today tend to talk about it as an unseen magical force. And when it is explained with this way it ends up being as helpful as someone explaining that a computer runs because of magic.
The problem we run into with chi is that there are expectations and preconceptions that tell us what chi is from popular culture. So if there isn't a light show and wind rushing around us then we are just a bunch of crazy people breathing heavy and waving our hands about. It is impossible to knock a person down without making contact with them. No I lie it is possible to psychosocially make a person think your knocking them down but not very practice (if anyone wants to prove me wrong I would be happy to be a mental punching bag). But this is not chi, it is clever! but not chi.
There are explanations of chi that are based on the religious side of things. This is where we show respect for a cultural origins of the term however we must not mix this term for the martial term of chi.
Chi is common sense, by understanding the dynamics at work when a body is in motion and a bit of practice, you can at best do the really really really really really hard but not the impossible.
Sometimes your understanding of how something works is wrong, and you meet people who do something you thought was impossible but this simply means you need to rethink your understanding.
Well I hope this gets some comments out of you!!