If the current market collapse is "different this time," then there's something to worry about. If it isn't different this time, even if it's as bad as the great depression, there's less to worry about (in the past the market has always bounced back).
So, do you think it's different this time (e.g. peak oil, overpopulation, things got too far out of whack) or not (e.g. hangover from irrational exuberance, normal housing price cycles, naughty bankers)?
The main difference between now and other times in history is the amount of leverage that corporations have put up. This is a direct result of the buyout financing binge of the 1980's and the ability of computers to model profitable buyout opportunities and hedge funds to take advantage of these models by borrowing huge amounts of money for LBO's to then reemerge as new "efficient" companies, though now with little room for error in the execution of their plan. Therefore there are far far fewer AAA rated companies than any time in history as competitor companies had to leverage as well to compete and get stock market price growth.
Companies have been labeled fools if you didn't go out and borrow money to buy back your stock.
Therefore as the economy goes into a slowdown similar to those times corporations are not having the ability to have "solid" assets to back their long term plans. Companies do not have the funds to buy their own stock as they did in 1987 when that financial problem was forestalled to today. A sign of this is the record decline in dividends as companies just don't have the funds to pay them shows the financing problems are real not imaginary. And that earnings have been overinflated over the past years due to the leverage in corporate America provided unsustained growth.
Golden examples of this are GE and DOW. They are both now so overextended they are in need of the government to bail them out, whether by loan guarantees for GE or the government to upend contract law as for DOW, instead of going out and picking up cheap companies and setting themselves to come out of this situation flying, they are turning to the US goernment and Warren Buffet to save them.
So we end up in a situation where the US govenrment lends/invests hundreds of billions to corporations with a capitalization of less than 25 billion because they are "too big to fail".
And instead of the world's future growth coming from a free and relatively debt free country to help crawl out of the economic morass from a populations overextention as the United States was in 1929, now we are counting on a corrupt regime in China for the world's growth.
USATODAY.com - As company priorities shift, fewer get AAA debt rating
What will happen only time can tell, it may have fallen far enough already, but I am reminded of what I read about the great depression , "At every corner we thought we had come out of the worse time in history when in reality it was only beginning, it appeared happened so quickly but yet in slow motion."
Letting it fall and having something to invest whenever this ends will result in being able to set yourself up quite well for life.