I have been very successful in my scientific work, and have become one of the best known scientists in the world. I have three children and three grandchildren so far. I travel widely, have been to Antarctica, and have met the presidents of Korea, China, India, Ireland, Chile, and the United States. I have been down in a submarine and up on a zero-gravity flight, in preparation for the flight into space that I'm hoping to make on Virgin Galactic. Despite my disability, I have managed to do most things I want. My main regret is that it has prevented me from playing with my children and grandchildren as fully as I want - Stephen Hawking with regard to ALS