Related:

• If at first you don't succeed, quit; don't be a nut about success.
• If at first you don't succeed, quit, quit at once.
• If at first you don't succeed, try try again. Then quit. No use being a damn fool about it.
• If at first you don't succeed, try, try, try again.
  Then quit. There's no point in being a damn fool about it. -- W.C. Field...
• If at first you don't succeed, redefine success.