Related:

• One person's constant is another person's variable.
  -- Alan J. Perlis, "Programming Pearls", Communications of the ACM, Sep. 1985...
• One man's Windows are another man's walls.
• One man's theology is another man's belly laugh.
• One man's nightmare is another man's wet dream.
• One man's upload is another man's download.
• AFVC: Add Finagle's Variable Consta
• One man's folly is another man's wife. -- Helen Rowland (1876-1950)