Tai Chi and Qigong, as well as all Chinese martial arts, begin training by copying and repeating techniques. Over time, these techniques become internalized and yield what is known as “gong” — the same word as “gong fu” (kung fu). This kung fu is the ability to express the principles of the art physically with your body.
The biggest mistake beginners make is to focus on the art intellectually and to try and understand or rationalize the principles of the art before being able to express them. It is good to understand what the principles are as a roadmap but no amount of “understanding” makes up for “perception”. It can also cause problems if there is a mistake in understanding because the student will miss or resist the correct training results later.
“If you want what I have, then do what I do.”