It sounds downright tiring.

You work your whole life in order to retire and enjoy some peace and quiet. Then, smack dab in the middle of your retirement planning process, someone tells you to figure out how to get three income streams during your Golden Years.

But there's a mountain of evidence to back up the claim. Perhaps the most convincing comes from Wes Moss, chief investment strategist for Capital Investment Advisors and host of the Money Matters radio show.

Moss conducted his own research on what characteristics happy and unhappy retirees share. The results, in terms of the number of income streams needed, speak for themselves.

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Author's charts, made using data from Wes Moss' You Can Retire Sooner Than You Think.

Yes, it is possible to be happy in retirement with less than three streams of income. Usually, however, that's because one has done a great job of saving during their working years. Sometimes, as you'll see, it actually has little to do with money, either.

No matter the circumstances, the facts make it pretty clear: happy retirees are over twice as likely to have three or more income streams than those who are unhappy. The good news for everyone is that it's easier than you think to get three income streams in retirement, without Herculean efforts.

Income stream #1: Social Security
Entire libraries could be filled with all that has been written about the fate of Social Security. While there are undeniable problems that will eventually need to be addressed, the system isn't going anywhere anytime soon.

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For an astounding 90% of retired Americans , the largest asset that they have to rely on as they age is their Social Security income. Between retirement age and when they pass away, Social Security will provide more for sustenance than savings, a pension, or home equity.

The silver lining is that even if no steps are taken to shore up Social Security's funds, the program will still pay out about 75% of current benefits. That might be little solace to those who rely heavily on it, but it's important nonetheless.

You can choose to start taking your Social Security at any time after the age of 62, but the earlier you take it, the lower your benefits are per month. For those born after 1960, 67 is the age of full retirement benefits, with even more being piled on for those who wait until after age 67.

Anyone who has earned a wage, or been married to someone who has earned a wage, is eligible for Social Security. To get a rough idea for how much the program could kick in for you, visit the program's website here.

Income stream #2: Retirement savings
There are lots of places that you can put your retirement savings: traditional IRAs, Roth IRAs, company 401(k) plans -- the list goes on and on. The important thing to recognize is that by doing a good job of saving and investing right now, you're creating a meaningful stream of income during your retirement years.

There's no one-size-fits-all approach to retirement savings, but the following is the most tried and true advice you'll find when it comes to maximizing what you have: do whatever you can to get your maximum company match on 401(k) plans, open up a Roth IRA and max that out, and if you still have money left over, put it back in your 401(k). Along the way, be sure that you're making sure to keep your investment fees as low as possible.

If you're looking to get an idea for how far your retirement savings can go, remember this simple rule: most advisors recommend that you withdraw 4% of your savings in year one, and then adjust that amount to match inflation thereafter. So, if you have $500,000 in retirement accounts, you can safely withdraw $20,000 per year. It's not a hard and fast rule, but it gives you a ballpark estimate.

Income stream #3: Part-time work
I can hear some of the groans already: "It's not retirement if we have to work!" 

To that, I have this to say: "it's not work that you want to retire from, it's mandatory work that you have little to no control over and don't like."

It might surprise you to know that one of the greatest challenges the newly retired report having  is sadness and loneliness over the loss of social connections that were previously enjoyed because of employment.

There are lots of ways to deal with this that will not only provide income, but also revitalize your spirit. The first is to turn your hobby into a passion. Maybe you like woodworking, or bird watching -- you can turn that into part-time income by fixing pieces of furniture, or offering tours at your local wildlife sanctuary.

If you don't think earning money from your passion is possible, there are always low-stress, part-time jobs available: everything from a ticket-taker at professional sports games to a substitute teacher to a crossing guard. These jobs might not pull in a ton of income, but their benefit is two-fold: they add cash to the previous two revenue streams, and they provide the opportunity for meaningful connections beyond your working years.

It's also worth stating that if you start collecting Social Security before full retirement age, and you are earning over a certain amount, some of your benefits will be delayed until you hit full retirement age--which is 67 for those born after 1960. To get all the specifics, check here.

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Part-time retirement work: a little cash, a lot of connections. Photo: baldeaglebuff, via Flickr

And just like that, with a little time committed to a part-time job in your Golden Years, and smart planning during your working years, you have three income streams to rely on in retirement!

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