1. "Self-taught students must first restrain themselves" means: Self-taught people must first restrain their selfish desires and be strict with themselves.
2. "Self-taught students must first restrain themselves" is from the "Differentiation of Style" part of "Elegance on Calligraphy". This part generally means that calligraphy is like people, only the human heart is different. Their faces appear from the inside to the outside.