Apple (NASDAQ:AAPL) is hands down the most closely followed stock of the last decade. The Apple rumor mill has made a habit of highlighting every product leak and speculating about every report, and analysts persist in chasing the stock price with their always-moving 12-month price targets.

In the past three years, the media's hyperactive Apple coverage has been particularly aggressive. Reporters have held up a microscope to the stock's wild volatility, attempting to justify each and every swing.

AAPL Chart

AAPL data by YCharts

But when investors zoom out from the microanalysis of every detail surrounding Apple's business and observe the stock from a 10,000-foot view, there are three simple lessons for long-term investors.

Do nothing
Sometimes, the best move an investor can make is to sit back, relax, and do nothing. This strategy has worked out handsomely for buy-and-hold Apple investors for decades -- and the last three years were no exception.

Investors who owned Apple stock during the last three years -- ignoring all the noise and avoiding the guessing game of attempting to time the peaks and troughs -- have earned solid profits. In spite of the volatility, Apple stock has soared 72% in the past three years. Additionally, the company has paid out a total of $5.30 in split-adjusted dividends during this time.

Sure, investors who managed to perfectly time selling Apple stock around a split-adjusted $100 in 2012, and proceeded to buy shares when they pulled back to close to $55, would have outperformed long-term buy-and-hold Apple investors. But it's difficult to imagine that the same sort of investor who would cash out around $100 in 2012 and buy around $55 in 2013 would have the patience to hold through the stock's massive run-up to $130 today.

At $55, Apple stock was a steal
When Apple stock pulled back to $55 in 2013, the keen investors who acted on this irrational overreaction to the company's narrowing gross profit margin and slowing revenue growth at the time have earned about a 134% return on their investment in just two years.

While buy-and-hold investors are often better off ignoring volatility when it comes to the shares they already own, this doesn't mean investors shouldn't look for buying opportunities when stocks on their watch list pull back.

Indeed, volatility is often a buy-and-hold investor's best friend. When a market selloff sends shares of excellent companies to irrationally low prices, long-term investors can add to their positions or finally open a position in the excellent business they've been eyeing.

Share repurchases matter
One of the primary drivers behind the rise of Apple's stock price in recent years has been management's aggressive share buybacks.

By repurchasing loads of its own shares, Apple has been able to grow its earnings per share, or EPS, significantly faster than it has been able to grow its net income. TTM EPS in the past three years has risen 33%, easily outperforming Apple's 19% growth in net income during that same period.

AAPL Net Income (TTM) Chart

AAPL Net Income (TTM) data by YCharts

Repurchases also explain the difference between Apple stock's gain and the company's market cap increase. In the past three years, the stock leaped 72% on a 52% market cap gain.

Summing up these three lessons, there's little reason to pay attention to the majority of market noise concerning excellent businesses. Sure, Apple had investors wondering about the company's growth potential in 2013. But the concerns hardly justified a nearly 50% sell-off between the stock's 2012 high and its lowest point in 2013. Long-term Apple investors who held this industry-leading cash cow amid all the noise have made out like bandits.