blackrock.com). If you are under 40 you could live 50 years and more. If you are 20 something you can expect your life to last more than 60 more years.
This has important implications for investing. You could invest parts of your money for more than 20 years when you are 60 and for more than 50 years when you are 30 or younger.
History shows what gains you could expect when you invest over a long span of years. Take for instance the S&P 500 as a gauge for the U.S. stock market (wikipedia). In March 1962 the index moved around 70 points (wolframalpha). Since then its value multiplied with the factor 20, that implicates that every dollar invested then is now worth $20. Someone who invested $5,000 in March 1962 and stayed in the market has now $100,000. If you take a 30 year period, for instance from 1982 (wolframalpha) to today, then an invested dollar would be multiplied with a factor of 12. If you start the calculation in the spring of 1992 you would get the factor 3.5. All these periods & calculations include the naughty years since 2000 and the ugly recessions.
Maybe the next 20, 30 and 50 years are even better then the past. Globalization and the catch-up process of the emerging markets should drive global wealth and stock markets higher. And it looks like the technological progress is accelerating (drivebycuriosity). Rapid innovations in computing (including iPads & iPhones), engineering, robotics, nanotechnology and other fields could speed up the pace of economic growth and therefore generate continuosly rising profits on the stock markets.