Law came from a humble normal family of Doctors. Lost his family and his whole life tragically. Worked and studied hard. Got knowledge in medicine to make his fruit work. His fruit that requires immense stamina to even wield and requires vast medical knowledge to make it work. Trained his haki to near Yonko level.
Yes. TRAFALGAR D WATER LAW is the most self made chaddest character in the whole of One Piece