Lesson #1: Risk drives return.
Lesson #2: Diversification within asset classes and allocation across asset classes are the cornerstone of controlling any given level of risk.
Lesson #3: The best anyone can do over time is to get a market rate of return.
Lesson #4: Investing is for the long term.
Taken from : Making Sense on the Dollar, by Scott K. Anderson, Jr. , ®, EA