Certainly is tough -- I'm in my mid 30s, so still a youngin', but have been through a few very ugly market downturns. While all the evidence certainly supports the "it will get better soon enough" mindset, I don't think many people for example expected oil's downturn to go so far or last so long, with no imminent end in sight. Things can certainly get much, much worse before they get better.
The most concerning thing for me is a feeling that the market is increasingly more and more volatile and erratic, and atleast to my sense less and less "rational". Reading Michael Lewis' Flash Boys last year really damaged any last vestiges of faith in the underlying integrity of the markets themselves -- particularly when you understand how much high frequency traders have to gain from extreme volatility - in either direction.