Oh. Em. Gee. What just happened?!

I was just about to rake in a stack of Benjamins with a time-sensitive killer trade, and then -- BLAMMO! Denied!

That was bad -- as in, "worst day ever" bad! You know, up there with that stuff that happened on May 6, 2010, August 1, 2012, and those few days in November 2012 -- I'm not exactly sure what that was all about. But I'm sure that ruined someone's day, for real.

WWWD?
Of course, none of that stuff even crossed your mind yesterday when the New York Stock Exchange halted trading from 11:32 a.m. to 3:10 p.m., right?

Of course not. Instead of constantly refreshing your brokerage account page, CNBC, your day-trading cousin's Facebook page, Twitter, Instagram, Friendster et. al., you paused for a moment for reflection -- a moment during which you asked yourself: What would Warren Buffett do?

Thanks to the extensive archive of the Berkshire Hathaway (BRK.B -1.18%) CEO's famous letters to shareholders, we know: When traders and commentators and gamblers are all going crazy, it's a safe bet that Buffett will do nothing. Nada. Zip.

In fact, Buffett long ago provided an instruction manual for the very scenario that went down on Wednesday: "Only buy something that you'd be perfectly happy to hold if the market shut down for 10 years."

A decade without refreshing your stock quotes? Ten whole years without contemplating the perfect moment to zig and then zag? Three thousand six hundred and fifty days of inertia?

The better question: What did you do?
It may have been a relief to commitment-shy investors that the NYSE resumed trading after a few hours, and we didn't have to spend years just staring at the companies in our portfolios. And that's a shame.

But what we did get on Wednesday was 3 hours and 38 minutes of quiet time to practice our deep-breathing exercises, slow down our pulses, and, most importantly, exercise our impulse control.

When the day was finally over, the major indexes (the Standard & Poor's 500 (^GSPC 0.24%), the Dow Jones Industrial Average (^DJI -0.29%), and the Nasdaq Composite (^IXIC 0.97%)) basically yawned and shed less than 2% of their value. That's a fairly ordinary day on the stock market.

Thursday morning, it was back to business as usual. So did you learn anything about yourself during this "teaching moment"? 

Now what?
You just got the chance to take your investing temperament out for a test drive. How did you do? Where did you fall on the investor-speculator spectrum?

Remember, investors buy solid businesses with the expectation that they'll be rewarded over time. Investors don't try to time the market and don't speculate, even though they, like everyone else, suffer from occasional hand-wringing, sleepless nights, and the temptation to do anything but sit on their hands.

But in the face of computer glitches, temporary flash crashes, bad quarters, bad hair days, and other events that grab headlines and fuel panic, investors remind themselves to chill out and not fixate on day-to-day movements.

When investors feel the urge to take action, the best ones use their time to find profits in panic and opportunity amid chaos. So if you didn't have the chance during yesterday's 3-plus hour investing "time out," now's a great time to run a fire-drill on all of the stocks in your portfolio