Mushoku Tensei: Isekai Ittara Honki Dasu

A 34-year-old NEET dies in a traffic accident and finds himself reborn in a world of magic—not as a grown mage, but as a newborn baby. Though his new body cannot yet move properly, he retains all the memories of his former life. Resolved never to repeat the mistakes of his first existence, he vows to live his second chance without regret. Possessing the knowledge of a middle-aged man, he becomes a prodigy by the age of two, wielding power unimaginable for anyone his age or even older. Thus begins the chronicle of Rudeus Greyrat, son of the swordsman Paul and the healer Zenith. As he enters this new world, he strives to become the strongest mage known to man, with abilities rivaling even the gods themselves.