"It takes ten years to sharpen one sword"
This is a common Chinese proverb that one says to an impatient person. The origin of this comes from a Tang Dynasty poem roughly translated as "Swordsman," by Jia Dao.
Anything great takes time and effort to accomplish. In martial arts, mastery of a technique takes practice. Therefore, a person should not be discouraged when they do not execute a technique correctly at first. One needs to accept that they are a beginner and continue practicing.