Before the classics

The tai chi classics are not the root of tai chi.
To extend the metaphor; they are the tree trunk, with the various schools and families representing the branches and leaves.

The root of tai chi is taoism.
Taoism is not about tai chi and never mentions tai chi, but everything in the tai chi classics presupposes an understanding of taoism and its associated principles and insights.

If you are not familiar with Tao Te Ching and Chuang Tzu, you should expect to find the tai chi classics difficult.
Lao Tzu spoke of how his insights were nothing remarkable yet no one would implement them. His book Tao Te Ching is a clever piece of literature; it is so utterly understated and easily ignored.

The title tells you its worth: The Way Things Are And Their Inherent Power.
In other words: accord yourself with existence and you will draw strength from your relationship.
This lies at the centre of tai chi chuan.