Why I don't really care
Now, this may still end up being a more serious situation for stocks and my net worth could go much lower.
Thankfully, I feel fine. I'm even slightly hopeful that prices will continue falling until I can buy again in January. After all, I'm going to be buying stocks for at least the next 28 years: why would I want them to be expensive?
Paper losses aren't real until you sell the assets in question. My very simple philosophy is to never sell and buy things that look cheap/good/interesting. It's not an optimal strategy, but I think it should do me okay.
Of course, if I was going to be needing the money in the next five years or so, I might be worried at this point.
That would be a sign that my portfolio was out of whack. The closer you are to needing the money, the more conservative/defensive your investments should be. That's the point of the 'your age in bonds' rule of thumb.
How are your investments going? Are you hoping for higher or lower markets?