[deanmoriarty]

The true test will come at the next downturn, my speculation is that most of the people who buy index funds because the "shoeshine boy" told them, will panic and sell, realizing significant losses. Shortly after, more active traders will come in and reap the rewards by buying at the bottom (e.g. like Buffett did in 2009).

I believe if you continue holding (I will) you'll do fine if we don't face a catastrophe, but you certainly need to have some sort of financial discipline to see your net worth slashed by 30%+ and stay still.