Art of Kung Fu

I have been watching the Netflix show Marco Polo. In Season 1, Episode 3 (Feast), Marco Polo’s teacher explains the deeper meaning of kung fu.

What do you mean by this word “Kung fu?” Does it mean “to fight” or as the Shaolin monks say, “to summon the spirit of the crane and the tiger?”
Kung fu means “supreme skill from hard work.”

A great poet has reached kung fu. The painter, the calligrapher – they can be said to have kung fu. Even the cook, and the one who sweeps steps, or a masterful servant – can have kung fu.
Practice, preparation, endless repetition. Until your mind is weary, and your bones ache. Until you are too tired to sweat, too wasted to breathe.
That is the way, the only way, that one acquires kung fu.