Your confidence level is what will determine your success level in the workplace.

That's proved true again and again for the most famous entrepreneurs, the smartest business leaders, and the most talented managers.

If you lack confidence, you won't be able to confront people about problems on a team. If you question your talents, you'll pause as someone else swoops in and steals the show on a sales or marketing team. Wallowing in self-pity, complaining when other team members get a promotion, wishing you had more opportunities instead of grabbing an opportunity with both hands--these are the hallmarks of those who lack confidence.

Yet, the question is--how do you gain confidence? Should we all go back to business school? Embark on a sojourn to the wilds of Africa for a few years?

I'm convinced that confidence does not come from any inherent traits, your education level, or even what you look like in a mirror. Confidence is a decision you make...when you get up in the morning, when you arrive at work, when you walk into a meeting. You decide to be confident, and those who excel in their jobs are the ones who make that decision every single day. They don't decide on Mondays to be confident and forget by Thursday. Also, they are not wearing an S-shaped emblem on a superhero uniform with a flowing cape; they have not solved world peace; and, they are not Brad Pitt. They have a set of accomplishments and maybe a degree from an institution, but the real differentiator is the decision to speak, act, and demonstrate confidence on a daily basis.

Here's an example of how that works.

Let's say someone offends you at work. Oh no! Call in the cavalry! Why don't you set up a meeting with that person to resolve the issue? For those that complain to everyone else or sulk around with a titled coffee-cup in their hand, it's a confidence problem. You go directly to that person as a decision to seek resolution, and it's not because you know everything. You do know that, at the end of the day, you believe in your own abilities and experience up until this second of the day--whatever that may be--and you approach the situation knowing that resolution is possible. Interestingly, when you show enough confidence to resolve conflict you also build more confidence for the next problem.

What about the person who hasn't decided to have confidence? There an unraveling that occurs, like a piece of yarn pulled to the breaking point. Self-analysis, second-guessing, a timid demeanor. You assume, one way or another, that you will probably fail. Like someone about to run a marathon, you reach the starting gate with everyone else but the thought bubble above your head says "this is not going to work out" and it doesn't.

You plan to fail. Your confidence is lost.

There's another way to approach that starting gate. It's all about the assumptions you make. Decide, right now, to have confidence. Decide, right now, to walk into the meeting with the knowledge you have and approach every business conversation as one that will lead to a positive outcome. Invest in your own self-confidence like you are loaning money to a friend and expect that there will be a return on that investment. Leave the second-guessing to someone else in the office. Break the pattern about bad assumptions related to your own work performance and your own outlook on life.

When you do, amazing things happen. Your confidence is what carries you on to the next promotion, the next sales victory, the next career milestone. It's like the wind in a sail, but you're the one who is setting the course and providing the power you need to excel.

What's holding you back from deciding to be a confident person right now?

Published on: May 12, 2017
The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.