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
It's dark outside As soon as Te Shan crossed the threshold he said, "Long have I heard of Lung T'an (Dragon Pond), but now that I've arrived here, there's no pond to see and no dragon appears." Master Lung T'an came out from behind a screen and said, "You have really arrived at Lung T'an." Te Shan bowed and withdrew. During the night, Te Shan entered Lung T'an's room and stood in attendance till late at night. Lung T'an said, "Why don't you go?" Te Shan bade farewell, lifted up the curtain, and went out; he saw that it was dark outside, so he turned around and said, "It's dark outside." Lung T'an lit a paper lantern and handed it to Te Shan; as soon as Te Shan took it, Lung T'an blew it out. Te Shan was vastly and greatly enlightened. Yuanwu Keqin, Thomas Cleary & J.C. Cleary, The Blue Cliff Record In a state of reverberation