I got really lucky with the crash. I had just signed up with a financial adviser at Morgan Stanley around April 2008. By Nov 2008, my net worth went from $400k down to $250k and my portfolio was doing worse than the market. I had always managed my own finances prior but thought a financial adviser would do a better job. It's funny now looking back. The adviser actually purchased some Lehman bonds. If the crash didn't happen, I might still be with Morgan Stanley.
My adviser didn't take the breakup very well. Before he got my money, I was his best drinking buddy. When he had my money, I became a distance relative. Finally, when he lost my money, I became his ex-wife. Anyways, it took a month to liquidate and close the Morgan Stanley accounts. By the end of Dec 2008, I was all cash. This was really lucky because the market recovered off the 2008 lows in Dec 2008. I keep all cash thinking the market was heading back down. The gods of market-timing should have smote me but the market reached new lows in Mar 2009. Two weeks after the bottom in March, I reinvested all the cash. I did smarten up and bought broad-based ETFs. Between 2009 to 2013 I put all my savings into the market every month with the exception of buying a house in 2011.
I think what helped me the most was that I started investing in 97 and lived through the dot com bust and Sept 11. If the world hasn't ended after those events, I was fairly certain the market would recover.