A work/life balance is difficult to strike even in normal times. But now that home has become the office for millions of Americans, work hours are bleeding into personal hours. It's more important than ever not to tie your entire identity — and, in particular, your life satisfaction — to the thing you do for money.

"Work life, generally speaking, you ride a roller coaster," said Art Markman, a professor of psychology and marketing at the University of Texas at Austin, and the author of the book "Bring Your Brain to Work." "Not every day is a good day, there are projects you work on that don't always go well, and if you're doing anything interesting that has to be the case."

"If everything you have going on in your life is focused on work, it means your entire life rides the roller coaster," he said.

Early in many Americans' childhood, our identity becomes inseparably tied to our jobs. We're conditioned to tie our core identity to a profession.

As we grow into that mind-set, we embrace the idea that a career is a singular force pushing our lives forward. If we're lucky enough to be good at what we do, it can be difficult to have perspective, said Alison Green, founder of the advice blog "Ask a Manager" and author of a book of the same name.

"If you're conscientious and you like what you do, it's very easy to get your identity all tied up with your job," she said. "There is this dark side to it that you don't really spot until it's no longer a force for good in your life."

It's important to protect yourself from letting problems in one area of your life affect the other areas, especially now that the borders between every aspect of our lives are blurrier than ever. A bad week at work is a drag on your mental health, but if your work is only a part of your identity, and not defining it completely, the overall emotional impact of that bad week is less severe.

"The problem with having your identity tied up with your job is that it's not fully within your control," Green said. "If things start going badly at work, it can affect your mental health in ways that it wouldn't if you weren't so deeply invested. So it's giving work a lot of power over your happiness in ways that can end up hurting you."

She added that centering your life on a job may even make you act against your own self-interest and happiness, perhaps by working long hours or accepting behavior you normally wouldn't.

"The brain needs a little downtime," said Markman. "You can't sustain concentration. Unless you can get away from the problems you're trying to solve in your work life, you don't give your brain a chance to reset and come up with a different way of characterizing what you're dealing with. So even if your primary goal in life is to be as productive as possible at work, you need some time away to make that happen."

This doesn't mean you shouldn't be invested in your work or not care about your career and the people you work with. That investment can be an asset, and being passionate about one's work can help lead to better output. Rather, give that investment a ceiling.

"You're playing the long game here," said Green. "It's one thing to work into the evening for a few weeks or months, but it's not sustainable long term. You want to manage your career with an eye toward what you can keep up."

In the first months of the pandemic, Green said she heard from many people struggling to separate work life and personal life for the same reason: Everyone at work knows you don't have anywhere else to be. The solution, according to Green? "Just start putting the boundaries in place."

This could mean not answering your phone or e-mail after your workday has ended, or not engaging with a Slack message while you're taking a 15-minute mental health break during the day. Often, Green said, "when people just start carving out those boundaries for themselves, they discover it's fine. Nothing happens, no one even notices."

Of course, that doesn't work for every job. So if you're nervous about creating boundaries, have a conversation with your manager and explain that you're trying to create a schedule that's sustainable — and healthy.