Modern Portfolio Theory (MPT) and the Efficient Markets Hypothesis (EMH) have influenced portfolio management strategies for an entire generation. Taking the example of an average Canadian family from 1977 to 2016, this paper examines how well MPT and EMH served the baby-boom generation of investors. A model investing strategy was constructed based on the principles of MPT and EMH. The strategy was evaluated for its ability to adequately provide for the subject couple in retirement. Results of this portfolio were compared to other popular investment alternatives. Using generally-accepted rules-of-thumb in financial planning, the MPT strategy was found to have provided an adequate retirement income for the subject couple. Some of the other strategies moderately exceeded the returns of the MPT strategy, while others underperformed this benchmark. Analysis of these discrepancies reinforced the significance of diversificaton and of rebalancing portfolios through dynamic asset allocation.