Remember the mission. What does "don't forget your initiative" mean?

It means not forgetting your original thoughts and will, and forging ahead like a sword.

Just don't give up your original idea, and try to complete and realize it. This passage comes from Empresses in the Palace.

Biography is a philosophical work, written by China's philosopher in Ming Dynasty and a representative of Neo-Confucianism in Song and Ming Dynasties, Wang Shouren (word Bo 'an), known as Mr. Yang Ming. This book records his quotations and letters about learning.