Related:

• None are so empty as those who are full of themselves.
• Spock: "Is it possible...that we too, you and I, have grown so old and so inflexible, that we have outlived our usefulness?
  Would that constitute a joke?" -- "STVI:TUC", Stardate 9523.8...
• None are so fond of secrets as those who don't mean to keep them. -- C. C. Colto
• It is not the critic who counts, or how the strong man stumbled, or whether the doer of deeds could have done them better.
  The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly, who errs and comes short again and agai...
• No fools are so troublesome as those who have some wit. -- La Rochefouccauld
• It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better.
  The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly...
• Enthusiasm
• There is none so bigoted as a liberal who will permit no view but their own. -- Bob Early
• I have the greatest enthusiasm for the mission - HAL 9000