Near the end of 2008, when the Dow was down about 35% I started to go in a little at a time with Roth money, like a monthly DCA (I bought 600 shares of AAPL first when it was about 12.50--my wife had already bought a long-term stake of 700 shares for 12.31 in 2007) in our shared taxable brokerage. Everything bottomed in early 2009 at around 45-50% I was back in fully by some time in 2010. I made out huge on the AAPL stake, selling at about 93.00 in 2012. The price of AAPL then crashed about 40% a little while later, and I bought in again at 60.00, but a much larger stake--doing the most ill-advised move ever. I liquidated all other holdings in the Roth and put it all in AAPL! I remember thinking at the time that the AAPL crash didn't make sense to me. That it was making money hand over fist, and that it would come back. I then sold it all when it reached 110.00., nearly doubling my Roth balance. I've since diversified. And now it's all cash again, except for those long-term holdings in our taxable brokerage.

Occasionally, I feel stress from investing, but most of the time, I'm having fun. I pull out when I get that gut feeling.