It was a cold and windy night. I was walking carefully down the slick city streets, when suddenly the skies opened up with a splitting crash and released a torrential downpour. As I struggled with a broken umbrella, I saw him, leaning casually against a wall, as if the rain couldn't touch him. My hero. He sauntered slowly toward me. I stopped struggling with the umbrella and stared at him, eager for his protection. He tossed my useless umbrella away without hesitation and slowly opened his coat. The next thing I knew, the rain couldn't touch me, either. When I looked up, all I could see was numbers. And the numbers I saw stopped my heart.

I had fallen in love. But even though no man would capture my heart for years to come, this fund's prospectus was the key to making my heart pound. With a low expense ratio, excellent performance, and a trustworthy manager, I had found my match. Add to that the ease of investing for a young girl who was afraid of risking her money, and I was hooked.

A dream come true
The Vanguard Target Retirement Fund (FUND:VTIVX) was the love of my life. Amidst a plethora of investing choices, I was overjoyed to see a one-step investing solution that did all the work for me. Never again would I have to struggle to decide between the IBMs and Dells of the world. As busy as I was, straight out of college and working to prove myself, this fund of funds gave me the confidence to start investing right away.

The Vanguard Target Retirement Fund focuses on asset allocation, which is a crucial component to creating a balanced portfolio. Depending on how many years you have until you retire, the fund automatically refocuses your asset allocation on a gradual basis. So you could start out with a 99% allocation to stocks and then allocate a higher percentage to bonds as you get older.

I trust the managers of this fund -- the Qualitative Equity Group (QEG) at Vanguard. I worked at Vanguard after college, and I grew to respect and admire the talent of Gus Sauter, the head of the group. After examining the group's performance, I had found one more reason to pick this fund -- overall, the Target Retirement Fund has returned more than 13% in the past year. That's not bad for an easy, breezy dream date.

You make me feel .
It's easy. The fund allocated most of my money to the Vanguard Total Stock Market Index Fund, which has General Electric, Exxon Mobil, and Citigroup (NYSE:C) as its top holdings. Those three companies alone have contributed about 50% returns since I bought shares in this fund, although the majority of that is admittedly from Exxon's rise on the oil wave. Overall, the Total Stock Market Index Fund has returned almost 13% in the past year. That's a nice contribution to my Target Retirement plan.

In addition to a Total Bond Market Index Fund, the retirement fund of funds also includes the European Stock Index Fund and Pacific Stock Index Fund. These added stalwart companies such as BP (NYSE:BP), HSBC (NASDAQ:HBC), GlaxoSmithKline (NYSE:GSK), and Toyota (NYSE:TM) to my all-in-one portfolio.

The fund's expense ratio is a minimal 0.21% -- a small price to pay for access to so many companies.

Undoubtedly, the love of my life eased the stress of making my first investment decision. It made me feel carefree, knowing that I did the right thing by investing. That's what you call love.

Share the love
Although that 13% return was stress-free and a lovely addition to my life, I am at heart a greedy individual. I want more. So, sadly, I was unfaithful to my love. I branched out. You might say I went from being a one-fund gal to being an investing hussy.

I flirted with Microsoft. I eyed Johnson & Johnson (NYSE:JNJ) from across the room. But in the end, I gave my heart away to Pixar. And it's a good thing I did, too, because just a little while later, Disney (NYSE:DIS) came and took us under its mighty wing. Spreading the love around was a good thing.

I diversified my portfolio and became less dependent on the Target Retirement fund. It's nice to know I have that fund as the backbone of my portfolio, and that leaves me room to experiment with stocks, REITs, and other asset classes. A little fund adultery never hurt anyone.

Fall in love all over again
Finding that one fund to be the love of your life can be hard, but it's well worth the effort. You get to leave your heart (and money) in trusted hands, pay low fees, and earn great returns at minimal risk. Investing in funds doesn't have to stifle your portfolio. Think of it, rather, as a way to maximize your portfolio's returns.

You, too, can find that special fund regardless of your investing experience. In the Motley Fool Champion Funds newsletter, Shannon Zimmerman has recommended more than 30 different sweethearts for you to choose from, 87% of whom are beating their respective benchmarks. Each one meets its specific set of criteria -- performance, expenses, and management (the tall, dark, and handsome ones of the fund world). The list includes funds that focus on international stocks, real estate, or even the health sciences. What more could a girl ask for?

Take the newsletter for a 30-day spin at no cost to you, and fall in love all over again.

Take a look at the rest of today's package:

Microsoft is a Motley Fool Inside Value recommendation.GlaxoSmithKline is a Motley Fool Income Investor pick, and Pixar is a Motley Fool Stock Advisor selection. Dell has been recommended by both Stock Advisor and Inside Value.

Motley Fool research analyst Shruti Basavaraj recommends falling for funds that don't break your heart. She owns shares of Pixar, Microsoft, and Johnson & Johnson, as well as every fund mentioned in the article.