Hello
This contains a very profound philosophy. From the perspective of calligraphy, the writing of each Chinese character has a process of inheritance, transformation and combination. It pays attention to the flexibility of brushstrokes, the reasonable shade of ink, the coordination of size and style, etc. The word "一" is no exception. It can be said that the word "一" contains the inspiration, mentality and skill of the calligrapher.
The famous saying "One word is the most difficult to write" by the master of traditional Chinese painting Li Kuchan illustrates an extremely common and profound truth, that is, to achieve a career, you must have solid basic skills.
Hope the answer can help you