Related:

• Constants aren't; variables don't.
• Murphy's: All constants are variables!
• Variables won't; constants aren't.
• Osborne's Law: Variables won't: constants aren't.
• A math student is pestered by a classmate who wants to copy his homework assignment.
  The student hesitates, not only because he thinks it's wrong, but also because he doesn't want to be sanctioned for aiding and abetting....
• Oh, no! Don Ho!
• Universal Laws: "The Law of Volunteering" If you dance with a grizzly bear, you had better let him lead.
  "The Law of Avoiding Oversell" When putting cheese in a mousetrap, always leave room for the mouse....