Tom Brady's 4 mental tricks for success

The New England Patriots are facing off the Philadelphia Eagles at the 2018 Super Bowl on Sunday, marking the Boston team's eighth trip to the NFL championship since quarterback Tom Brady joined the team.

At 40 years old, Brady is the oldest active quarterback in the NFL and one of the oldest players in the league, according to NFL.com, and says he has his mental toughness to thank for his successful career.

"If you want to perform at the highest level, you have to prepare at the highest level mentally," Brady said in the new Facebook Watch documentary "Tom vs. Time."

In the new 15-minute-film, Brady said he finds that mental aspects of the game, like throwing the ball, making decisions and leadership, are more inherent to him than his physical abilities.

"I still work on athleticism — running and, you know, jumping — and do all those things that I need to do, but you know it's a very minimal part of what I do," he said.

Brady has been playing football professionally since he was a 22-year-old college graduate drafted to the Patriots. But the quarterback acknowledged he has always felt more mentally equipped for the game than physically equipped.

So today, one of his biggest priorities is making sure he has the right mental toughness and attitude, Brady wrote in his 2017 book "The TB12 Method: How to achieve a lifetime of sustained peak performance."

"Knowing what your strengths are and weaknesses are and trying to build on those things and being open to changing those things is something that I've really worked hard at and coached at," Brady said.

Here are four lessons you can learn from the mental tricks Brady uses stays mentally tough — during football season and off-season — and succeed in this career.

Focus on your strengths

In 2013, Brady founded his fitness and wellness organization TB12 with his body coach Alex Guerrero to share the training methods the two developed, as detailed in Brady's recent book.

Brady said he wishes he could tell his younger self to commit more to training physically.

"I wish I had did at 22 years old what I was doing for the last 10 years. I just didn't know any better," he said, referring to his new fitness and lifestyle habits.

In senior year of high school, Brady said he felt out of place because his teammates were always faster and stronger than he was.

"I always felt left behind," he said.

In "Tom vs. Time," Brady admitted that "being a late bloomer in some ways was helpful."

When he got to the professional league he said his level of excitement had him trying to chase everyone, pushing to get better-and offered him an openness to learn. But starting out, Brady said he knew he was "never going to be as good as those guys were physically."

"In 2000, the New England Patriots and their then quarterback coach Dick Rehbein chose me as the NFL's 199th draft pick, which, if you do the math, means that I was passed over by every team in the NFL somewhere between four and six times," Brady said.

Instead of letting this set him back, Brady remained motivated to target and improve his "deficiencies."

"Much of the success I've been lucky enough to have in my career I owe to a lifelong 'will-over-skill' mindset," he said.

Always treat practice like a game

According to Brady, he is always in competition with himself and such was the case when he realized NFL players trained twice as hard as his college team did.

A saying he carried over from college to the professional league was to always treat practice like a game.

"If I don't treat practice like a game, there's no way coaches will let me play in an actual game," Brady reasoned.

In order to gain respect from his coaches and teammates, Brady put in work.

"I worked my butt off every day in practice, knowing that if I didn't make the extra effort to treat every practice like a game it was unlikely that the coaches would ever let me play in an actual one," he said.

Train your brain

In addition to training his body, Brady makes sure to give his brain a workout as well.

"Another way to keep our brain as healthy as possible is to ensure they get the right amount of exercise through cognitive training," he said in his book.

Brady further argued that while creating a healthy inner environment through hydration and nutrition is good for you, it isn't enough.

He posed this question: "Does it matter what you eat if your mindset is negative or angry or if you have poor self-esteem?"

One of the simplest ways Brady said he takes care of his mind is by creating a regular routine for sleep. By going to sleep at 9 p.m. and waking up at 6 a.m., he gets nine hours of "uninterrupted therapy and regeneration."

Brady also uses neuroscience to train his body into forming new habits through a process called neural priming.

"To create stronger, faster connections in our brains, we need to practice a habit skill or behavior again and again," he said. "The more we practice that habit, skill or behavior, the more automatically our brains recognize it."

By doing daily exercises like running on a treadmill or using resistance bands, Brady said he feels better because his mind better recognizes it's time to work out.

Turn negatives into positives

When it comes to winning or losing games, there is one thing Brady said matters more to him than the outcome: the amount of effort he or his team put into the game.

"If I don't play my best, why am I disappointed? Because I could've, should've played better, done better, worked harder, prepared more," Brady said. "In the end for me it's less about the outcome than it is about whether I put in the best effort relative to our team's potential."

For Brady, many of his worst experiences in life have turned out to be his best experienced because it allowed him to learn a lesson.

"Because I found that challenges bring out the best in me, today I think back on them as gifts. I fought hard to get to where I am today, which means I know it means to fight hard," Brady said. "When you're in a Super Bowl game and your team is three touchdowns down and the clock is running, mental toughness is what makes the difference at the end."

"In turn, the right mindset and attitude give us opportunities to do the best we can and realize the potential that's in every one of us," he added.

Disclosure: NBC Sports is televising Sunday's Super Bowl.

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Video produced by Jon Fazio.