Apple is a great company and if you've owned stock for any reasonable amount of time, you are a happy investor. We can learn a lot about investing looking at Apple. We can learn plenty about Wall Street at the same time.
Apple was just about $100 in 2009 and has been $700 recently. Wow. Nice win SO FAR! Pretty much every mutual fund owns it by now.
Lesson One - good stocks continue to go higher, until they don't and usually without warning.
Lesson Two - even super great well performing stocks have significant pullbacks which is usually when supposed long term investors sell (and later wish they hadn't).
Lesson Three - eventually all growth companies and their stocks become too large to grow at the fantastic rates of the recent past and level out, Intel is a wonderful example, Microsoft too. With all that cash, they usually start to pay a dividend, are sold by growth investors and bought by value investors. Apple is very likely close to this.
Lesson Four - Wall Street will get it wrong again. Over forty brokerage firms cover Apple and only one has a hold rating, no sells and plenty of buys and strong buys. REALLY? It is reminiscent of the tech bubble when almost no analysts would dare tell investors to sell anything.
Do yourself a favor, if you own Apple, consider selling here around $700, probably a great chance you can buy it back at a lower price.