One of the first trades I made was to buy AIG on the crash. I knew nothing (relatively speaking) about AIG or the stock market but thought this would be a good chance to profit from panic. I did NOT profit. Thankfully it was a small amount of money and a very valuable lesson. I think that transaction forced me to become an informed investor.

Last year I sold and bought AA in a short turn around. I have neither the time, knowledge or value to be a short term "trader" and that investment is still on the books at a loss. DUMB move - but smart lesson.