Extinction was a difficult concept for a 10-year-old.
I had not expected 'A Brief History of Time' to be a best seller. It was my first popular book and aroused a great deal of interest. Initially, many people found it difficult to understand. I therefore decided to try to write a new version that would be easier to follow.
Because atomic behavior is so unlike ordinary experience, it is very difficult to get used to, and it appears peculiar and mysterious to everyone - both to the novice and to the experienced physicist.
Let's face it; by and large math is not easy, but that's what makes it so rewarding when you conquer a problem, and reach new heights of understanding.
I enjoy popularisation and I think I'm reasonably good at it. I also think it's a duty. It's just so pedagogically stupid to forget how difficult one found these ideas oneself to begin with.
Though a simple book can be written on selected topics, the central doctrines of economics are not simple and cannot be made so.
Definitions are temporary verbalizations of concepts, and concepts- particularly difficult concepts- are usually revised repeatedly as our knowledge and understanding grows.
