Don't be a Drop Out!
When markets take a dive, think before you make a drastic decision. Consider how these three investors behaved during different market conditions over the course of 40 years. They all diversified, and their portfolios grew less risky as they aged—but they still ended up in different places.
Check out this one page graph put together by Charles Schwab describing 3 different investors: The Stalwart, The Reactor, The Waffler.