Success is no cakewalk. It takes every ounce of perseverance and strength you've got. That includes mental strength. And some people seem to have an advantage here, i.e. the mentally strongest individuals (whose inner strength leads to outer success--think Elon Musk and Oprah Winfrey). Such mental strength yields better decisions and more positive mindsets, which any entrepreneur or leader can benefit from. 

The mentally strongest have four powerful habits in particular that typify their fortitude and that foreshadow future success. Emulate them by doing these four things.

1. Don't lose sight of your anchor.

It's easy, especially in times of change, to lose sight of your core, your most closely held values. Remembering your values in times of adversity is a source of strength, resolve, and perspective, and keeps you grounded.

Values are those little things we do each day that exemplify who we are. They're the daily little impressions that leave a huge permanent impression. If I asked you to write down your most closely held, non-negotiable values, could you? My survey work conducted in classes I teach at Indiana University indicates that only 30 percent of people can write down their non-negotiable values within any reasonable time frame.

If you fall into the 70 percent, take some time for introspection to write your values down and keep them in front of you. If you can do that, it makes you much more likely to live each day in support of your values versus in spite of them. It's greatly helpful in times adversity, as it's during such times that our true character shows, aided by our values. Our values are the arm around our character that holds it steady and guides it down the right path.

2. Resist pummeling yourself with disempowering self-talk.

Everyone on the planet at least occasionally fires up the engines of self-criticism. It's the mentally strong who catch it immediately and cut off the fuel lines.

It's not hard to fall into a pattern of pummeling yourself with negative self-talk, a downward spiraling of limiting thoughts, beliefs, and attitudes. We often don't realize we're doing it and even when we do we still can't help ourselves. It's like we can't give away our power fast enough.

So why do we do it?

For my book Find the Fire, I enrolled a hypnotherapist to help me understand this toxic tendency. She told me the root of it all is a corrosive self-belief that we're not good enough. It's a belief often born from a misperception, a slight taken the wrong way, an irrelevant comparison that sends us into a tail spin.

And it's exacerbated by how we think about our differences versus others, which is to say, we think our differences make us lesser than, when in truth, they make us greater than. You simply must believe this. The most mentally tough, successful people do.

3. Don't fall victim to comparison.

I teach not falling into this trap and I still fall into this trap--when I compare myself with something or someone who doesn't matter, and it makes me feel lesser than.

Sometimes, the enemy is the internal me.

But to regain my mental fortitude, I quickly recall that the only comparison that matters is with who I was yesterday and whether or not I'm becoming a better version of myself.

4. Strive for authenticity versus approval.

When we seek approval, we're seeking external validation, which is an empty victory at best and soul crushing at worst. When we seek approval, we worry about what the universe wants and thinks--especially if we're people-pleasers (something I still struggle with).

But when you seek authenticity, you don't worry about the universe, you worry about the "youniverse," meaning you know that you self-determine your self-worth. What you're worth, how you're valued, is based primarily on how you view it. You worry about living up to your standards, not someone else's.

Here's a powerful tip to help you do that: Live by the 90:10 rule. This represents a ratio of 90 to 10, a formula for how to calculate your worth, which is to say it should be based on 90 percent self-worth, 10 percent assigned worth. How you feel about yourself should flow dominantly (90 percent) from your own self-acceptance and self-appreciation. Purists might not agree with allotting 10 percent for external validation, but I'm a realist. Becoming completely callous to the occasional signal that you're valued and loved is unrealistic. 

That said, you get into trouble when you focus more on winning love, rather than giving love. And don't confuse winning love with having personal worth, they're not the same, so treat that external validation for what it is, 10 percent of the equation. 

So flex your mental strength by forging these four habits. The likelihood that success follows is strong.