At the age of 21, Stephen Hawking was diagnosed with amyotrophic lateral sclerosis. He couldn't walk without help first and after a point he was restricted to a wheelchair and couldn't speak anymore. In spite of the physical limitations, he found a way out, by taking the help of a computer-based communication system. In that state, he wrote and co-wrote 15 books, the first one being on the best-seller list for four years. When the first book wasn't as easy to understand for some, he followed up with two other books to further simplify his theories. This way we can say that Stephen Hawking was a versatile personality.