A question for beginners: If an investment keeps you up at night, is it worth it? Photo: Sander van der Wel, via Wikimedia Commons.

When looking to give advice on investing for beginners, I always return to one tip: remember why you're doing this in the first place. That simple suggestion could help turn what can be a gut-wrenching, anxiety-producing activity into one that serves your pocketbook and gives you peace of mind.

My family invests for a simple reason: to allow us the freedom to focus on nonfinancial matters that are important to us. Knowing that, here's why I consider one of my worst investment decisions to be the best choice I've made since I began putting our money into the stock market.

An investment that got personal
Back in 2010, I made the first of several purchases of Netflix (NASDAQ:NFLX). Not only was I enamored with the service, but I found co-founder and CEO Reed Hastings' approach to running his company to be very refreshing. He was someone I wanted to invest with.

By the end of the year, the original investment had almost quadrupled. In April 2011, my wife and I made another substantial purchase of Netflix stock -- at a cost of $240 per share.

Then rough waters began appearing. First, Netflix raised prices on its streaming service in a way that didn't sit well with customers.

I didn't have a problem with the price hike, or the subsequent drop in the stock -- after all, it's best not to worry about short-term movements. It was the fashion in which it was done that rubbed me the wrong way. I penned an open letter to Hastings about this, and to my surprise, he responded.

In the end, he apologized and let me know that the extra money was going into original content. As we all know by now, that has been a pretty good choice. At the time, I thought the only choice Hastings had was to disrupt his own business model, and believed it would work out for the best.

Behavior that kept me up at night
But then came a series of events that really made me worry. The company announced that its DVD-by-mail business would be spun off into a separate company, dubbed Qwikster. Just days after the announcement, Netflix reversed course and essentially took it all back.

Then, in 2012, the SEC opened an investigation into Hastings' decision to post relevant company information on his Facebook page instead of filing an 8-K. Taken alone, the filing, which asserted that Netlfix subscribers viewed 1 billion hours of content in a single month, wasn't that big of a problem. But in the back of my mind, I began to seriously question if Hastings' behavior was becoming increasingly erratic, and if this was a developing problem for him, the company, and investors.

In late 2012, we sold all of our Netflix shares for under $65 per share. Taking all of our separate purchases together, we did so at a considerable loss.

As many of you know, the company's stock has rebounded fantastically since then. Hastings strategy of focusing on original content while expanding operations abroad has proven to be a brilliant business move. And what I once thought of as erratic behavior hasn't proven to be a long-term problem at all.

Had we not sold our shares, Netflix would be one of the biggest winners we've ever had.

And yet, I still think selling was one of the best decisions I've made. The reason why is an important investing lesson for beginners.

Remember why you're in the game
In 2012, just before we sold our Netflix shares, I spent countless hours at night wondering what to make of the Hastings situation. At a time when my usual nightly worries surrounded whether the Milwaukee Brewers were winning or if my wife and I would make it to happy hour with friends, I was consumed by a stock in my portfolio.

It was then that I remembered why we started investing in the first place -- so that the focus could remain on the things that mattered to us (the Brewers, happy hour with friends). Selling our shares allowed me to refocus on those important parts of our life.

Beginning investors need to keep this in mind. You're probably going to have stocks that do very well, and some that do very poorly. If you diversify, and keep it all in perspective, these movements should not cause you to lose a wink of sleep at night.

Remember: You're not going to catch every multibagger, and there's a chance you could lose some money. But if, in the process of investing, you're able to get what you need to support yourself and your family, while experiencing all that life has to offer and not worrying too much about money, you've succeeded as an investor.