If anyone has friends/family who believe that the stock market boom will continue ever upward show them this chart which illustrates the Dow Jones over the last century and has recessions marked on it. The longest period between recessions in the US was November 1990-June 2001. We are overdue a recession by historical standards. see the chart below:
http://www.macrotrends.net/1319/dow-jones-100-year-historical-chart