A version of this post was originally posted on Forbes. Sign up for Caroline’s newsletter to get her articles sent straight to your inbox. “Cool girlfriend syndrome” is the term I gave to my tendency to act chill and low maintenance so my boyfriends would love me more. If that’s not bad enough, millennials do the same thing in our careers all the time: But it gets us into trouble. In this example, overworking can actually undervalue you, as I wrote about in my Forbes article on why millennials aren’t getting promoted. To get promoted, writes Slade Sundar, COO of Forte Interactive, Inc., “you’ll need to prove you’re more than just a nose-to-the-grindstone type.” Here’s another example of cool syndrome: Committing to projects without knowing what we’re doing sabotages our chances of learning things right and getting better. We become known as someone who will take on anything nonchalantly but do a mediocre job. At the end of the day, people who pretend to know everything aren’t trainable, nor are they good collaborators or leaders. A final example: Sometimes millennials think that if they just put their heads down and do good work and don’t complain, they’ll eventually be recognized and rewarded. But, as I’ve covered before, this is rarely the case. Researchers at the University of Notre Dame found that less agreeable employees earned an average of 18% more annually than their agreeable coworkers. Those who demonstrated more agreeable traits were, conversely, less likely to receive promotions. Research also shows that we tend to think agreeable men will make worse leaders. Of course there are millennials on the opposite side of the spectrum, who are entitled and pushy. But I believe many millennials fall into the former category: we’re trying to get ahead gently, with style, and it’s not working. There’s another, more existential concern I have about cool syndrome. It eventually blurs the distinction between what we know and don’t know, like and don’t like, need and don’t need. Eventually we realize that we haven’t stood up for ourselves in months, that we’ve sacrificed our life for little reason, and that we’ve been pretending for so long that we don’t even know who we are or what we want anymore. We might look like we have it together, but our careers are coolly falling apart. Here’s what I’ve learned about cool girlfriend syndrome: The girlfriends who say “Oh nothing” aren’t more lovable. They’re just annoying. In our relationships and at work, people want others to be open, vulnerable and fallible. If your company, or your significant other, doesn’t value you for these fundamentally human traits, they should hire a robot. If you liked this article, sign up for Caroline’s newsletter to receive more like it!