The person who knows "How" will always have a job. However, the person that knows "Why" will always be his boss!

After Thomas Edison's fame had become international, he was advised to have scientists come to his lab and help him understand just why some of his inventions had worked. Edison didn't see much use for it, but being open-minded, he consented to the idea. As a result, a brilliant research scientist from Germany came to his lab to explain the principles behind some of his innovations.