Almost all this thread confuses two things: 1/ being
competent on one field 2/ being able and willing to share
especially with newcomers.
in reply to Second rate programmers and my confession
To be a good teacher requires both abilities plus
the skill to assess the knowledge and interests of ones audience so as
to start from the know to lead to knowledge of the unknown.
Having both abilities is more the exception than the rule.
I studied maths with teachers who were imposed the Bourbaki
style (formal maths). They were good teachers but they were
required to teach stuff that they did not really understand. Too bad.
Later, in engineering school (not a math-only cursus) I had as teacher who was a moron
who will stay unnamed. He was certainly mastering topology but was unwilling
to give examples because it was betraying the generality of
the theory. Most people learn from concrete examples and
later see in what generalization differs from these examples.
Also, the art to hook an audience without getting off
topic is a rare ability. See Conway and Dominus.
stefp -- check out TeXmacs