Related:

• Opportunity knocks but once.
• All that glitters has a high refractive index. -- Anon.
• Time is nature's way of keeping everything from happening all at once. Anon.
• It's OK, once you get past the hard exterior. -- Anon.
• Once a word has been allowed to escape, it cannot be recalled.
  -- Quintus Horatius Flaccus (Horace) (65-8 B.C.)...
• Once a word has been allowed to escape, it cannot be recalled.
  -- Quintus Horatius Flaccus (Horace)...
• The day of individual happiness has passed. -- Adolf Hitle
• Only after the last tree has been cut down, Only after the last river has been poisoned, Only after the last fish has been caught, Only then will you find that money cannot be eaten.
  -- Cree Indian Prophecy...
• Opportunity may knock only once, but temptation leans on the doorbell.