What does it take to achieve success? You’ll have many definitions for possible answers to that question.

To billionaire investor Mark Cuban, however, success may not involve accumulating mass wealth, as he has.

The “Shark Tank” regular offered up a surprisingly simple take on success in an interview with Steiner Sports:

“To me, the definition of success is waking up in the morning with a smile on your face, knowing it’s going to be a great day. I was happy and felt like I was successful when I was poor, living with six guys in a three-bedroom apartment, sleeping on the floor.”

How do you wake up in the morning these days? Better yet, when things haven’t reached your version of that ideal state, are you as content as Cuban was when he was poor? 

Cuban’s take is a huge lesson, whether you’re struggling to make rent or challenged by making payroll. His lesson is about attitude, and how one chooses to think, regardless of circumstance. In other words, it has everything to do with optimism.

Dr. John Medina, a developmental molecular biologist and author of Brain Rules for Aging Well, maintains that optimism is crucial for increasing brain health and slowing down of your aging process. He tells Forbes optimism can actually increase a person’s life span by nearly eight years and is a force against fighting off stress and disease. “The ability for you to stay optimistic produces a buffer against your probability of experiencing depression,” states Medina.

3 ways to instantly increase your optimism

If you’re not exactly cut from the fabric of that cheery, happy person who is the life of the party, don’t worry; nobody is asking you to change personalities. But changing your attitude about life may drastically change things for the better.

Psychologists have found that taking the time to think about good things that might happen in the future can increase our optimism. Researchers say journaling is the best method to get your brain to the positive, including engaging in any of these three writing exercises:

1. Journal about your “best possible self.” 

Research participants who wrote about their future goals and envisioned life as they imagined it (what researchers call your “best possible self”) experienced more positive emotions immediately after the task and reported higher well-being even several weeks later.

This written exercise, done in a few short minutes, is effective because it amplifies people’s awareness of who they are and what’s important to them. 

Your turn: Imagine your life in the future and that everything has gone as planned. Now write about what you imagined.

2. Journal about a positive or happy event. 

Think of something wonderful or amazing, perhaps one of the happiest moments or most ecstatic experiences of your life. Now spend a few minutes to write about it. 

In one study, participants who journaled about something positive from their lives, as opposed to participants who wrote about a neutral topic, reported higher levels of positive emotion immediately after writing and were less likely to pay a doctor’s visit for illnesses over the next few months. 

3. Journal two minutes of gratitude.

Harvard-trained happiness researcher Shawn Achor, the New York Times best-selling author of The Happiness Advantage? says your brain at positive performs significantly better than at negative, neutral, or stressed.

This means that a more positive brain gives you a competitive advantage at work. Achor says the brain at this state can increase your productivity by 31 percent.

One simple journaling exercise to trigger the brain to this positive state is to write down three acts of gratitude in as little as two minutes per day. ​Achor says that if you do it for 21 straight days, you’ll be training your mind to scan for positives instead of negatives.

This activity is the fastest way to teach optimism. It will significantly improve your optimism and raise your success rates even six months later.

This article was originally published on Inc.

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