First thought: ten years ago! For my wife and I, a universe away from where we are now (newly retired, different geographic location.)

Second thought: why did I do what I did, fall of 2007? Perhaps a pre-disposition to think "out-of-market," not that I was directly invested.  Like millions of others, I had all my assets in mutual funds. My wife had been, but pulled out 2 years  before and, ten years ago, was spending more time studying (technically and strategically) how to invest through our home computer. Fairly adventurous, back then. 

Me? In a word, it was "volatility." It seemed to have been increasing. Called my financial planner--remember the call well--and told him, "I just don't like what I see." Emptied the funds. Never forget his reaction: in word and tone he indicated that he AGREED with my decision. I safeguarded my retirement that day. 

Phoned my Dad the next day: he calmly told me had pulled everything out a few days before.

I'll never forget it. Nor what came next.