Dress for the job you want, not the job you have is the old adage for how young go-getters should approach cultivating an appropriate corporate aesthetic. Even as workplaces get increasingly casual–the person occupying the job you want may well be wearing a hoodie and cargo shorts these days–the idea that on-the-job success involves focusing on the future vs. the present is an entrenched one, reports Forbes.

But is having your eyes on the prize instead of on your immediate responsibilities really the best way to get ahead?

If you ask successful CEOs, the answer is no. In a recent New York Times piece, Adam Bryant distills some of the wisdom he’s heard from speaking to over 500 CEOs for the paper’s Corner Office column. One of the key themes he found was that, instead of being particularly forward-minded, these executives focused on excelling in their roles at the time and that their track record of success was the metric by which they were judged when climbing the corporate ladder. Bryant writes:

That may sound obvious. But many people can seem more concerned about the job they want than the job they’re doing. That doesn’t mean keeping ambition in check. By all means, have career goals, share them with your bosses, and learn everything you can about how the broader business works. And yes, be savvy about company politics (watch out in particular for the show ponies who try to take credit for everything).

This notion of treating what you're doing today as leverage for what you want to be doing tomorrow is a pervasive one. It’s very obvious to spot when someone you’re working with has decided that getting a promotion matters more than getting their work done. They’re all  "fresh" ideas and special projects and meeting agendas. They’re devouring articles like “10 Ways To Demonstrate Leadership Potential Before You Become A Leader” (a made-up title that probably exists somewhere; apologies to the author) and, yes, dressing for the job they want and not the job they have. And, more likely than not, their day-to-day work is suffering because they’ve now decided it’s beneath them. Maybe they get humbled and told that while their initiative taking is great, it can’t come at the expense of meeting this month’s sales quota. Or maybe it works. Maybe they get that promotion. And maybe the one after that.

Eventually, however, they hit a brick wall, because they’re not really good at anything other than figuring out how to get promotions. That’s their greatest skill. They don’t have subject matter expertise because they haven’t cultivated it in previous roles. They don’t have great workplace relationships because they’ve just been using their colleagues as guinea pigs on which to practice their “leadership” skills. And if things ever hit the fan and they’re called on to get into the trenches with their team and get their hands dirty with actual marketing/engineering/accounting tasks? They wouldn’t have a clue where to start.

Make no mistake, I’m not arguing for being an overly trusting worker bee. The days in which you could toil away while assuming your boss had your best  career interests at heart, if they ever existed, are long gone. Don't blunt your ambition. Consider your work in transactional terms and understand that the only person truly invested in your success is you. But also exert some effort to be good at what you're doing today. Do it, if not for the sake of personal pride and a useful habit of striving for excellence, at least with the understanding that it limits your chances at the C-suite to do otherwise.