u/aimixin - originally from r/GenZhou
In a sense it is a return to the past. China used to be one the largest economies in the world and most powerful nations before the Century of Humiliation. The Qing dynasty was slow in its development of the bourgeoisie and western Europe outpaced it, eventually European countries, primarily Britain, developing into an imperialist power. The Qing dynasty was behind and unable to muster the strength to combat imperialist aggression and was raped and pillaged by imperialist and colonial powers, falling into immense poverty. Rejuvenation just means undoing this and restoring China as a major world power, and relative to other nations at its time, a developed country.