Thor (Marvel Comics)

"Now you face the Mightiest Avenger of all!"-Thor

The young Thor was raised alongside Loki, who had been adopted by Odin after Loki's father, the Frost Giant Laufey, had been killed in battle. From childhood Loki was jealous of Thor, and his hatred of Thor grew over the years to a wish to destroy him. Thus began Loki's enmity for Thor, which persists to this day. At one point, Adolf Hitler succeeded in contacting Thor and deceived him into aiding the cause of the Germans, the descendants of the people who had once worshiped him, in the current war. Thor therefore clashed with the Invaders and nearly killed the second Union Jack with a blast of lightning from his enchanted hammer. Learning that Hitler was evil, Thor vowed to aid him no more, and withdrew most of the electricity in Union Jack's body back into his hammer, somehow restoring him to health in the process. The second Union Jack now possessed the superhuman power to discharge electrical bolts from his body. Odin decided that it was time Thor learned humility. Odin had Thor surrender his hammer to him, and then sent him to Earth in the mortal guise of a crippled young medical student named Donald Blake, stripped of his memory (again) of his true identity. As Blake, Thor learned the value of humble perseverance in dealing with his injured leg, and he came to care for the sick and dying, first as a medical student, and later as a successful physician. After leaving medical school, Blake opened a private practice in New York, and quickly gained renown as a great surgeon. After Thor had spent ten years in the role of Blake, Odin planted within Blake's mind the suggestion to take a vacation in Norway. There Blake encountered a party of alien Kronans, also known as the Stone Men from Saturn. Blake fled from the Kronans into a cavern, the very same one that had served as Thor's birthplace millennia ago, where Odin had left Thor's hammer in the enchanted form of a wooden cane. Trapped in the cavern by a great boulder, Blake struck the boulder with the cane in frustrated anger, and was transformed back into his true godly form of Thor. As Thor he escaped the cavern and drove off the Kronans. At first Thor still had no memory of his past life as an Asgardian god, although as months passed, more of his memories returned. Finally, a few years later, Odin revealed to him the false nature of the Blake identity and the reason for it.(From Marvel Database)

Thor maintained his Blake identity on Earth and continued his medical practice. Part of his affinity for Earth was his subconscious realization that his maternal heritage was on this world. The other part was simply his love for humanity and his need to experience those things that only mortals could know. Thor came to divide his time between Earth and Asgard, and does so to this day.