According to Wikipedia, Kung Fu (功夫)(gōngfu) means
"achievement
through great effort".

It has also been stated that it means "energy and time".  This alludes
to the fact that it takes much practice and experience to make any
achievement.

Without dedicated full effort, your martial arts will be nothing.

To be true to yourself, do not not be lazy.  Be diligent.  Do not be
half-hearted.  Commit to your training. Concentrate intently on your
activity thus sharpening your skills to the point of habit.

Good luck in your life long effort!