Watching Apple Computer (NASDAQ:AAPL) shares take a gravity defying dive yesterday, despite producing better-than-expected quarterly results, must have been painful for shareholders. Then again, that single event may have also inducted the company into the Growth Stock Hall of Fame.

See, that's what happens when a stock soars to the point of discounting even the best scenarios. A few years ago, when Apple was trading for little more than its balance sheet greenery, even bad earnings couldn't rock the moribund stock lower. Apple has grown up now. It's a growth stock, and investors need to learn that volatility cuts both ways.

Back in January, I made a series of unpopular predictions. Probably the worst-received was that shares of Apple were going down. The stock closed at $70.46 that day. With the stock now down to $37.26, I think I pretty much nailed this puppy.

What?

There was a 2-for-1 stock split along the way? My prediction was also for all of 2005, and the stock started out the year at $64.40 -- or a split-adjusted $32.20? Oh, OK. I'm still fabulously wrong then.

I'm still holding out hope that my other January predictions will continue to pan out -- including the promise of better days for Krispy Kreme (NYSE:KKD), TiVo (NASDAQ:TIVO), and Sirius (NASDAQ:SIRI). However, I still think it's important to temper one's enthusiasm when it comes to Apple because expectations are so high.

I mean, you can disregard yesterday's stock dip because the company's report truly was spectacular. Apple sold a ton of iPods and Macs this past quarter, but it sold more at an average price that was lower than last year. That really isn't much of a surprise. Computer product price cuts were made public, as was the company's move into entry-level iPods. It isn't a fair reason to mark the stock down. While lower average selling prices usually signify margin contraction, that wasn't the case with Apple. The bottom line actually skyrocketed.

Yet that's what happens when you price perfection into a stock. While the company is clearly on track to obliterate Wall Street's expectations for Apple to earn about $1.11 a share this year -- which means the stock is trading for less, perhaps significantly less, than its year-ahead P/E multiple of 34 -- longs shouldn't fret a little pessimism creeping back into the stock. Relish it. That's usually the best way to assure that the next time the company delivers better-than-expected news that the market will behave appropriately.

P.S. -- Go Apple!

More Apple stories that have fallen from the tree:

Longtime Fool contributor Rick Munarriz still likes Apple, deep down inside. He does not own shares in any of the companies mentioned in this story. The Fool has a disclosure policy. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early.