Many people spend years counting down to retirement. But while it's definitely a milestone a lot of folks get excited about, it sometimes end up being a disappointment.

If your retirement isn't what you expected it to be, then you may be considering joining the workforce again. Here are a few reasons to look at unretiring.

A person at a kitchen table looking sad.

Image source: Getty Images.

1. You're spending down your nest egg too quickly

It's a great thing to come into retirement with a nest egg you've built up. Some seniors kick off retirement with no savings at all, so if you started with some, you're ahead of the game there.

But one thing you don't want to do is spend down your savings in short order. That money may need to last for several decades, so it's important to take conservative withdrawals, especially early on in retirement.

As such, if you find that you're spending your funds more quickly than expected, then you may want to consider unretiring for a few years. That way, you can build your savings back up and, just as importantly, avoid tapping your cash reserves for a period of time.

2. You're lonely

It's one thing to retire in conjunction with a bunch of friends and a spouse who can keep you company and join you for outings and activities. But if you're pretty much the only one in your family or social circle who's retired, then your days might get lonely pretty quickly. And that's reason enough to return to work.

The nice thing about holding down a job is that it gives you not just income, but other people to be around. And even if your colleagues aren't your best friends, it's nice to have people to talk to during the day.

3. You're bored

You may have friends you meet up with weekly for gardening club, coffee, and meals. But even if you have access to company as a retiree, you might still find that you're bored to a notable degree. This especially holds true if you're someone who needs to keep busy constantly and doesn't do well with downtime.

If that's the case, returning to the workforce could be a good bet. There's perhaps no easier way to stay busy than by working. And if you don't think you can handle 40 hours of work per week, you may find that 25 or 30 hours gives you the perfect balance.

An option worth considering

If you were to unretire this year, you wouldn't be the first person in history to go that route. So think about whether retirement is really meeting your social and emotional needs, and be honest about your financial picture. You may find that going back to work for even just a couple more years is a smart move on a whole.

That said, if you're already collecting Social Security, you'll need to be mindful of how a return to work will affect your benefits. If you haven't yet reached full retirement age, you'll be subject to an earnings-test limit. And exceeding that limit could result in having some benefits withheld and paid back to you later on.

This isn't a reason to stay retired if it's not working for you. Rather, it's just something to keep on your radar.