At the Beginning, I Thought It Was Rebirth, but I Didn't Expect It Was Time Travel.

At the beginning, I thought it was rebirth, but I didn't expect it was time travel. In his previous life, my grandfather, who was hunched over and had white hair, turned out to be a master of spiritual practice who could split mountains. How can I live my whole life again in obscurity and achieve nothing? All-out cultivation, fights, high schools for cultivators, sects cultivating immortals, global cultivators competition...