Second, the Tweet from Carl with the quote from Rolfe. Again, might work for Wedgewood and the presumably well-off Rolfe, but, man, that frame of mind absolutely does not work for the average investor.

Rolfe seems like the type of guy who would admit this -- he's emotional right now. On one hand, he admits he made a bad call. He concedes he has to look at his position in AAPL closely. All good.

However, he's playing with fire -- and sending the wrong message to investors watching him -- by going against what the market gives him.

Valuation may never mean a damn thing again. I've been making the comparison between AAPL and names such as Amazon ( AMZN) and LinkedIn ( LNKD) for a while. Now, we throw NFLX back into the mix.

I'm not a valuation guy. I'm not calling irrationality here on AAPL on the basis of valuation alone. I'm calling it because we spend far too much time gauging Apple against its unwritten future and too little time assessing it vis-a-vis the reality of the current, subpar competitive landscape.

But, for better or worse, it is what it is. To dig your heels in -- because selling now would compound our original mistake, as Rolfe said -- are famous last words for so many investors. While that type of "strategy" might not blow up Wedgewood's account, it sure would crush quite a few retail portfolios.

There's a good chance that if you "stand your ground" (always be careful when you speak about a stock using such emotional language), AAPL will turn around, you'll make money, recoup any losses, gain back profits and look like a genius. But you have to resist that urge. Because, like so many other things in life, what you think is going to be a one-off thing often becomes a habit. And reacting with an emotional stubbornness will hurt you more often than not.

--Written by Rocco Pendola in Santa Monica, Calif.
Rocco Pendola is TheStreet's Director of Social Media. Pendola's daily contributions to TheStreet frequently appear on CNBC and at various top online properties, such as Forbes.

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