If You Think These 5 Things, You'll Never Get Rich by the Time You're 30 Five common mistakes entrepreneurs make when starting a business and how to correct them.

Last week, I had lunch with a millennial who wanted some advice about a business he's starting. After the usual small talk, we got down to discussing his business plan. Within a short time, it was clear that his business idea was great, his plan for executing was fairly solid and he had gathered together a strong team to help him make it happen.

So far, so good. But, to be frank, this guy has no chance of being successful with his current mentality. What it takes to be rich (or successful in any measure) has a lot more to do with your mindset than your ideas and plans.

From the time we started in business at the ripe ages of six and seven, our Grandpa Joe taught my brother Matthew and me many lessons about the details of running a profitable business. Over the years, we learned about how to create a business plan; how to market our products and services; and how to take care of customers, vendors and employees. All this knowledge has been invaluable to us in creating and running successful businesses. But, what our grandfather taught us about attitude and mindset trumps all other lessons.

Without calling out the specific individual I spoke with recently, below are five "hypothetical" attitudes that will get you nowhere in your journey to success -- and the attitudes that should replace them.

Related: The 10 Traits That Define Entrepreneurial Success

I deserve to be successful.

There's a lot of talk these days about millennials having attitudes of entitlement. I don't buy into that completely. I've met tons of people from this generation who are true rock stars. They know they have to earn success, and they're willing to work for it.

But, there are also people of every generation who think they have success coming to them. They had a hard life, they had to eat Ramen for years, their mom (or dad) left with the mailman when they were nine. So, they feel like they've paid their due.

Guess what -- life has been hard for all of us. There's not a person alive without a harrowing story of hard times they've gone through. Having to make it through hard times entitles you to nothing. The only people who deserve to be successful are those who work to make it happen. And failing once doesn't mean you deserve to make it the next time. Every endeavor is a new opportunity to create success. You learn from past failures, but they don't mean you've earned an easy ride.

Replace this attitude with: I will earn my success by working my butt off, doing the right thing and never quitting.

Success can come easily.

If you follow any marketing or coaching groups on Facebook, you're bound to find tons of posts that make it sound like success should be easy. "Make $30k a month while you sleep" or, "Part-timers are making six figures with this simple system!" are some of the headlines I've seen. People buy into this stuff, and it makes them believe that success without hard work is possible.

It's not. If the person selling their "easy path to success" system was for real, they wouldn't be selling it, they'd just be doing it.

Every single successful entrepreneur I know (and I've met thousands) has been through a roller coaster to get to where they are. They failed or almost failed many times; they wanted to give up; they sacrificed and worked harder than they thought they'd have to. If there are exceptions, I haven't seen them.

Replace this attitude with: Success is a struggle, but it's worth the work and sacrifice, and I'll come out a better person on the other end.

Related: The Most Common Habit of Self-Made Millionaires

I work smart, not hard.

You hear that phrase a lot: "Work smart, not hard." I understand what it's intended to convey, and I'm all for cutting the corners that should be cut. But, true success comes when you work smart and hard. Too often, people think this attitude means to find ways to get out of hard work or to somehow cheat the system.

What it should mean to you is that you can avoid working dumb by learning from your own mistakes and those of others who have come before you. You can make smart decisions that prevent extra, unnecessary work. Having to do the same thing over three times is working dumb. Doing it right the first time is working smart, even if it wasn't easy.

Replace this attitude with: I make smart decisions so that my hard work pays off more quickly.

It's all about me.

Okay, this is where I call out the guy I met with. Although he told me about his team, his primary focus was on how brilliant he was and what the success of his company would mean to him. In fact, about 95 percent of the time, he talked about himself and what he wanted. He's a nice guy, but it was fairly clear by the time we parted that he didn't have an interest in anyone but himself.

No one -- and I literally mean no one -- has experienced true success without other people being a significant part of their journey. Whether it's a mentor, a partner or your team of employees, you will only find true success when your motivation includes the well-being and success of those around you.

Replace this attitude with: I know I'll be successful when I focus on helping others in their journeys to success.

Related: 10 Things Successful People Tell Themselves Every Day

I know all I need to know.

It still amazes me when people who say they want my mentorship are more interested in demonstrating their own knowledge and accomplishments than listening to anything I have to say. Of course, I'm polite and give them kudos for how awesome they are, but I also think about the opportunity they threw away by spending time with someone who's been through every aspect of entrepreneurship for over 30 years. I'm not saying I know everything, but I do know some things about what works and what doesn't work in business, and I love sharing what I know. And at the same time, I'm always learning, as we all should be.

Regardless of your experience and knowledge, take the time to listen to people and be humble enough to know that you can learn something from anyone. Everyone you meet has had a vastly different life experience from you and, therefore, has a unique knowledge set. Be a learner, whatever level you're at.

Replace this attitude with: Everyone I meet can teach me something, and I'm eager to learn all I can.