Fixation is the way to death, fluidity is the way to life. This is something that should be well understood. - Miyamoto Musashi

It is difficult to know yourself if you do not know others.

Like a soldier, the carpenter sharpens his own tools. He carries his equipment in his tool box, and works under the direction of his foreman. He makes columns and girders with an axe, shapes floorboards and shelves with a plane, cuts fine openwork and bas reliefs accurately, giving as excellent a finish as his skill will allow. This is the craft of the carpenters. When the carpenter becomes skilled, he works efficiently and according to correct measures. When he has developed practical knowledge of all the skills of the craft, he can become a foreman himself.

In strategy it is important to see distant things as if they were close and to take a distanced view of close things.