Related:

• If A fool persists in his folly he shall become wise. -- William Blake
• Answer a fool according to his folly, lest he be wise in his own conceit. -- Proverbs, 26:5
• If a fool would persist in his folly he would become wise. -- William Blake
• Love may laugh at locksmiths, but he has a profound respect for money bags.
  -- Sidney Paternoster, "The Folly of the Wise...
• As a dog returns to his vomit, so a fool returneth to his folly.
  Seest thou a man wise in his own conceit? There is more hope of a fool than of him....
• Be wise with speed; A fool at forty is a fool indeed.
  -- Edward Young (1684-1765) -- Love of Fame, Satire ii, Line 282...
• Where ignorance is bliss, 'tis folly to be wise. -- Gray
• When ignorance is bliss, 'tis folly to be wise. GRAY
• Wise fool -- Oxymoro