Related:

• Quit while you're ahead. You may not get another chance.
• If you do that you have a chance of dying.
• Argue only when you have a chance of winning.
• Worf: "What have you found, Doctor?" Beverly: "Not much.
  The brain scans I've run are unusual, but there's no damage to the hypocampus....
• In the event your experiment works, do not give up hope.
  You still have the opportunity to come to the wrong conclusion....
• Someday you will get your big chance -- or have you already had it?
• Homer: Listen, Flanders, you still have that store?
  Ned: For two more days. [sniff] It becomes Libertarian Party headquarters....
• Someday you'll get your big chance -- or have you already had it?
• Hold still while I flame you. -- Karl Lehenbaue