For long-term investors, knowing the difference between what can and cannot be controlled is the key to both financial success and peace of mind. While all investors would like to believe they can predict or even control the direction of the market, experience teaches us that this is difficult to do. Constructing and managing an appropriate portfolio, while making strategic and tactical allocations based on market opportunities, ideally with the guidance of a trusted advisor, is often the best approach. However, while following markets and maintaining perspective on the economy is important, an even more fundamental key to success is simply to start saving early, stay invested, and remain focused on long-term financial goals. What can investors do to benefit from these principles today?