Related:

• Those who can, do. Those who can't, write the manual.
• Those who can, do; those who can't, Simulate.
• There are three kinds of mathematicians: those who can count and those who cannot.
  From: Norman Danner <ndanger@ocf.Berkeley.EDU>...
• There are 10 kinds of mathematicians. Those who can think binarily and those who can't...
• There are three kinds of people in the world; those who can count and those who can't.
  And the related: There are two groups of people in the world...
• Those who do not understand history shall repeat it.
• Those who do good will get their Just Punishment!
• Those who live by the sword get shot by those who don't.