Designer, implementor, user, writer A Fragment by Donald Knuth dl.acm.org Thus, I came to the conclusion that the designer of a new system must not only be the implementor and the first large-scale user; the designer should also write the first user manual. The separation of any of these four components would have hurt TeX significantly. If I had not participated fully in all these activities, literally hundreds of improvements would never have been made, because I would never have thought of them or perceived why they were important. Eating your own dog food making
A simple grain of sand "The desert will give you an understanding of the world; in fact, anything on the face of the earth will do that. You don't even have to understand the desert: all you have to do is contemplate a simple grain of sand, and you will see in it all the marvels of creation." Paulo Coelho, The Alchemist The history of all things