He doesn't have ALS but rather another form of neuro-muscular dystrophy related to it. I wouldn't exactly call him lucky - he is completely paralyzed except for his eyes. Hawking is definitely more famous than he probably would be if he didn't have his condition, but he is still very smart. He's done a lot of work with singularities and black holes, and discovered that black holes actually aren't completely black. The type of radiation they give off is called Hawking Radiation.