"The Ages of the Investor: A Critical Look at Life-cycle Investing" is intended to be the first installment in the "Investing for Adults" series. Just as grown-ups do not believe in the Tooth Fairy, the Easter Bunny, or Santa Claus, “Investing adults” know that there is no such creature as the Stock-picking Fairy or the Market-timing Fairy. Further, there is no Risk Fairy who will write you cheap options that will protect your stock holdings against loss. Investing adults are familiar with Gene Fama, Zvi Bodie, Jack Bogle, and Burton Malkiel, and understand that a mean variance optimizer does not blend vegetables. In other words, this series is not for beginners. Future topics will, with luck, include the limits of market efficiency and diversification in increasingly non-segmented global markets.