Not unemployment, as the longest I've been out of work since I was 16 is a week and a half.
No, it was the last recession that did it for me. I remained employed, but as a flat rate mechanic, just because you're at work doesn't mean your making money. If there was nothing to work on in a given day, I made $0.00. My annual income for 2009 was $30k lower than 2007.
I'm self employed now. Zero dollar days happen, but they are offset by the $1,000 days. My gross income is still lower than 2006/7, but net ends up about the same with the amount of write offs my type of business has.
'Course, I also have 3 little mouths to feed that weren't around in '07, so my days of "gun a month" (or more) are over for the foreseeable.
Fortunately, though, I learned my lesson after 2008. I hung in there for a couple more years, but had to file bankruptcy in 2010. I managed to refinance the house and settle the 2nd mortgate, and today I enjoy not having any monthly payments outside of mortgage, utilities and business expenses. No credit cards, no auto loans, nor any other type of outstanding balance beside the house. I drive a 13 year old Cadillac that I scored for $700 and sunk another $1,500 into parts, wife has a 14 year old SUV that I keep on the road, and we pay cash for everything. Life is much easier, much less stressful that way. And it means that whatever cash I have is mine; If you have $10k in the bank but owe $16k on credit cards and $32K on a car, then you don't actually have $10k.