In the Beginning of the Prehistoric Era, I Was Invincible but I Didn't Know It.

I traveled through time as soon as I woke up. Fortunately, there is a system, but the system is a bit useless. I can't draw draws or sign in. I can only study in the yard every day, calligraphy, cooking, breeding, planting, music, medical treatment, wood carving. Finally one day, I have learned all the things taught by the system, the system is broken, and a man named Cindy knocks on the door of his courtyard... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.