Thus, I came to the conclusion that the designer of a new
system must not only be the implementer and 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.

But a system cannot be successful if it is too strongly
influenced by a single person. Once the initial design is
complete and fairly robust, the real test begins as people
with many different viewpoints undertake their own
experiments.