Many people spend decades planning for retirement and count down eagerly until that milestone arrives. But sometimes, retirement isn't the wonderful experience seniors expect it to be. And if you can say yes to these questions, it may be time to unretire.

1. Are you depleting your savings faster than anticipated?

Ideally, you shouldn't retire on Social Security alone. Rather, you should have a solid nest egg you can tap to supplement the income you get from those benefits.

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But the savings you bring with you into retirement may need to last for 20, 25, or 30 years -- or more. And so if you find that you're spending down your nest egg more quickly than expected, it may be time to go back to work for a while and start earning a paycheck again. That way, you can boost your savings and help ensure that your money won't run out down the line.

Incidentally, if you decide to unretire and you're already collecting Social Security, you may be able to undo your filing and score yourself a higher benefit. You're allowed one Social Security do-over in your lifetime, provided you withdraw your benefit application within 12 months and repay all of the money you received.

Let's say you retired at age 65 and took Social Security right away. If now, 10 months later, you're not happy with retirement, you could potentially undo your Social Security filing, return to work for three more years, and then claim a higher benefit once you're ready to give retirement a second try.

2. Are financial concerns keeping you up at night?

It's natural to have some financial worries during retirement. After all, instead of bringing home money, you're spending the money you've worked hard to save.

But if your financial concerns are so extreme to the point where you're losing sleep, then it may not be worth it to stay retired. Instead, it could pay to return to a job and get the peace of mind of having a steady paycheck for a few more years.

3. Are you bored more often than not?

Some people wind up enjoying the slower pace of retirement -- not having to rush to an office or stick to a rigid schedule. But if you're overwhelmingly bored and restless in the absence of a job, then you might as well consider returning to work and earning a paycheck once again.

This especially holds true if you like your line of work, or if there's another line of work you're interested in pursuing. It's one thing to force yourself to return to a job you can't stand. But if you genuinely enjoy your work, there's no reason not to do it just because you've reached a certain age.

Retirement doesn't have to be permanent

A lot of people look forward to retirement only to realize it's not all it's cracked up to be. If that's how you feel, whether due to financial concerns or boredom, don't let that be a source of shame. Instead, own your feelings and act on them rather than force yourself to stay out of the workforce for no good reason.