It’s not until after you’ve learned the hard way that you realize not all advice is good advice. But when you’re just starting out as an entrepreneur, you can’t afford to take risks that might jeopardize your success. So how do you know which advice to trust and which to ignore?

We asked 12 successful entrepreneurs from Young Entrepreneur Council (YEC) the following question:

Q. As a business owner, you’ve likely received advice from many different people. What’s the worst piece of advice you’ve heard and why was it so harmful?

1. Follow Your Dreams or Passion

It turns out that dealing with tax issues, people issues, cash flow, customer complaints, and the hundred other challenges that come with running a business are not my passion after all! If you are serious about running a business, understand that while “baking” or “dog grooming” might be your passion, you’re going to spend way more time in the details of running a business. —John Rood, Next Step Test Preparation

2. Give People Second Chances

I know this sounds harsh, but if a hire was a huge mistake, don’t let them take advantage of you or your company again. So many owners give people second, third, and more chances when they shouldn’t. When we let go of an employee that we thought we couldn’t lose, every employee is relieved and the business runs smoother than ever. My rule is fire fast, hire slow. —Tommy Mello, A1 Garage Door Service

3. The Customer Is Always Right

This old adage is frequently shared (usually by well-meaning people), but it’s completely wrong for a startup. Especially when you’re in the service industry, it’s critical to weigh every customer request against not only what’s right for them, but also what’s right for your business. If you say “yes” to a request that’s outside your area of specialty, it can end badly for everyone. —Brittany Hodak, ZinePak

4. Grow as Fast as You Can

Everyone wants to grow their business as quickly as possible, but it can be dangerous to grow too fast. Take the time to make sure that the growth you’re experiencing is manageable in the short and long term. Make sure that you can easily scale your business to accept the growth before going out on a limb. Continually identifying ways to be more efficient goes hand-in-hand with stable growth. —Nicole Munoz, Start Ranking Now

5. Don’t Sweat the Small Stuff

The small stuff—the little inconveniences, details, and inefficiencies that are baked into everything—can make the biggest difference. I made my business that much better by working from the bottom to improve each and every part. Taking command of the little things helped me change the big picture. —Matt Doyle, Excel Builders

6. Stick With What Works

The worst piece of advice I ever received was “Once you find what works, stick with it.” While there is some truth to this, I think following that advice will lead to complacency. Of course, it’s important to figure out what works (and what doesn’t!), but you should always continue asking yourself how others can improve, what else they can be doing, and what you’ve outgrown. —Leila Lewis, Be Inspired PR

7. Wait and See What Happens

I missed opportunities by waiting when the market and economic cycles were down where I could have really established myself for the new positive upswing in the economy and realized bigger gains. It’s not necessarily a good idea to take the “wait and see” approach as you might miss the time where no one else was acting and you could have come out on top in a niche. Just go for it! —Murray Newlands, Sighted

8. Follow Your Instinct

I believe instinct is important, but it can’t be the only thing that moves you to action. I am a firm believer in doing your research and measuring those against what your gut is telling you. It’s really a combination of both that leads you to the best decision, at least in my own experience. Just going on gut can be more emotional than rational. —Zach Binder, RankLab

9. Don’t Develop Deep Relationships With Your Employees

I was told to not get to know my team on a more personal level. While it’s important to always maintain a respect level with them during business hours, I’ve found that developing relationships outside of the office can lead to stronger team camaraderie. It leads to more dedication at work, and employees who are invested in not only their own personal success, but the success of the team as a whole. —Bryanne Lawless, BLND Public Relations

10. Raise Money

Spend a day in any co-working space in any city, and the conversation will eventually turn to raising money. But the truth is most businesses should focus less on raising money and more on earning money. Outside funding is critical for some capital-intensive businesses, but for the vast majority of startups, it’s never been cheaper or easier to launch a business with a laptop and a website. —Richard Kershaw, WhoIsHostingThis.com

11. Never Trust Anyone in Business

The single worst piece of advice I’ve ever received was to never trust anyone in business. This advice is lethal because it suggests you should have an advantage in your business relationships. Early on in my career, I took this advice but quickly realized that in order for any business relationship to work, it must be mutually beneficial, and trust is an absolutely critical element of success. —Kristopher Jones, LSEO.com

12. Hire Based on Experience

An amateur mistake entrepreneurs make is hiring talent based solely on their work history and education. Some of the best employees I’ve ever recruited had non-traditional backgrounds for the roles they filled, yet they managed to outperform their peers in a matter of months. I truly believe passion drives everything, and people may surprise you when you give them the opportunity to truly excel. —Firas Kittaneh, Amerisleep