Hard work

Most new starters are not prepared for the amount of physical work involved in learning a martial art.

The image of tai chi creates a false sense of effortlessness.
Few people expect to train hard.

This is naive.

Set aside talk about relaxation, qi, softness and other concerns...
Your body is flesh and bone.
It is moved by muscles.
In order to be strong, agile, flexible and adaptive in combat - you need to strengthen your body.