"No injury, thankfully. And that's why I took a step back." 

That was Simone Biles's response to reporters yesterday, after she surprisingly pulled out of the Tokyo Olympic Games after already beginning competition.

The reason for Biles's withdrawal?

Biles said that she's been "struggling with some things," and felt the need to prioritize her mental health.

"I just think mental health [awareness] is more prevalent now in sports and it's not like we have to put everything aside. We have to focus on ourselves," Biles said. "We're human, too, so we have to protect our mind and our body rather than go out there and do what the world wants us to do."

No doubt, Biles will face major criticism for her decision. She's following in the footsteps of tennis superstar Naomi Osaka, who also recently withdrew from two major tournaments, the French Open and Wimbledon, to focus on her own mental health and spend time with friends and family.

But what the haters don't realize is that both Biles's and Osaka's decisions are proof that more and more young people are figuring out a major secret to success. It's a secret that most of their predecessors didn't figure out until years after their peak -- if they figured it out at all.

It's a lesson that benefits entrepreneurs, business owners, and just about everyone else -- and we can sum it up in a single sentence:

No one should define what success means to you, except you.

Let's break down exactly what that means, and why it's so important.

How emotional intelligence helps you define success and happiness

Professional athletes are often tempted to let others define success for them.

Think about it. Unless you wear a gold medal or championship ring, unless you can put on a green jacket or hold a trophy up high, you've failed.

Try again next year.

In the case of Biles, we have someone who has already achieved those goals. Someone who, at the ripe old age of 24, is already regarded as many as the greatest gymnast of all time.

Yet, somehow, pulling out of the Olympics because she fears getting injured is mentally weak.

Withdrawing because she doesn't want to hurt her teammates' chances of winning a medal is somehow "quitting" on her teammates -- despite the fact that she even stayed on the floor to cheer them on.

No, Biles isn't weak. 

She's emotionally intelligent.

Emotional intelligence is the ability to identify, understand, and manage emotions to achieve a goal. In this case, Biles recognized how the stress and pressure of performing under the bright lights on the biggest stage exacerbated the countless other problems she is dealing with, of which only she is aware.

Worst of all, it was taking away her love for the sport.

"I came in and I felt like I was still doing it for other people, so it hurts my heart that doing what I love has been kind of taken away from me to please other people," said Biles. 

"I feel like I'm also not having as much fun, and I know that this Olympic Games I wanted it to be for myself," she added.

Biles's goal never changed. She still wanted her team to win a gold medal. But even more importantly, she didn't want to jeopardize her own mental health (or physical health, for that matter) to do it.

This is such a key lesson for entrepreneurs, business owners, and anyone else trying to attain success. In fact, it's a lesson I've learned the hard way -- and continue to learn -- through building and running my own small business.

Over time, I came to realize that my definition of success is much different from that of others.

Yes, we could grow faster. Yes, I could work many more hours in a week. Yes, I could make much more money.

But at what cost?

Would I still love what I do?

Would I still have a happy marriage?

Would I still have a great relationship with my three young children?

And yes, you guessed it...

Would I still have my mental health?

It's easy to fall victim to others' criteria for success. We could easily translate questions like:

  • You haven't won a gold medal or championship yet?
  • You've only one won championship?
  • You haven't gotten a max contract yet?

To...

  • You haven't raised any funding for your startup yet? 
  • You're not a manager or supervisor yet?
  • You're not making six figures yet?

Don't pay any attention to those questions. They're designed to let others define success for you.

Instead, ask yourself questions like this:

  • What makes me truly happy?
  • How can I balance running my business or making a living with maintaining my own mental health -- and without jeopardizing my own happiness?

You don't have to win multiple gold medals or championships, or break world records, or build a billion-dollar company. Define success for yourself.

Because, in the end, those other things may actually stand in the way of getting what you truly want.