NFL running back Saquon Barkley -- arguably the sole bright spot in an otherwise forgettable New York Giants season -- is taking a page out of Marshawn Lynch's financial playbook. 

In 2016, Lynch gained widespread attention for reportedly never spending any of his then $50 million in NFL earnings and living off endorsements and other business ventures instead. (Although it turns out that he was, in fact, spending at least some of that money.)

Jay Leno has never touched a dime of his Tonight Show money, even though at his peak he reportedly earned $30 million per year. He made sure to always have at least two incomes; early on by working at a car dealership and doing comedy gigs, and later by hosting The Tonight Show while also doing as many as 150 standup appearances a year. 

"I always had two incomes," Leno says. "I'd bank one, and I'd spend one." 

And then he would always spend the lesser of the two. "When I was younger, I would always save the money I made working at the car dealership, and I would spend the money I made as a comedian," Leno says. "When I started to get a bit famous, the money I was making as a comedian was way more than the money I was making at the car dealership, so I would bank that and spend the car dealership money."

Barkley, who was recently named the NFL's Rookie of the Year, signed a four-year contract with the Giants worth a guaranteed $31 million, including a $20 million signing bonus.

He also signed major endorsement deals with companies like Nike, Pepsi, and Panini sports cards. (Plus, judging by his Twitter feed, Dunkin' Donuts.)

And he played a prominent role alongside legends of the game in the NFL's 100-Year Game Super Bowl commercial (coincidentally enough, so did Marshawn), which speaks volumes for his appeal -- and prospects for future deals.

"When I declared for the NFL draft," Barkley says, "and kind of realized where I was going to be drafted, I was like, 'You know what? Kind of want to follow the Marshawn Lynch method. I don't want to touch that. I want to invest it, put it in the right peoples' hands, and learn as I continue to make investments. And just live off the endorsement deals."

It's hard to fault that approach. An estimated 78 percent of NFL players face financial hardship within two years of retirement. (An estimated 60 percent of NBA players go broke within five years of leaving the league.)

Why? The average NFL career spans less than four years. If I earn millions of dollars in salary and spend like I'll always make that much money, once my career is finished, so is my money.

Athletic careers last a handful of years, so savings must last for decades. For professional athletes -- or for anyone -- beating the odds requires planning, effort, and discipline.

And a willingness to go against the grain.

Some of the time it pays to consider what other people think -- but not if it stands in the way of living the life you really want to live.

Don't buy a house just to impress other people; buy the house that's right for you. Don't buy a car just to impress other people; buy the car that's right for you. 

Make spending choices that are right for you. Make investment choices that are right for you.

Choose your career, your school, your business -- choose everything because it's right for you.

At the very least, you'll make better long-term decisions about your money. Which also means in time you will be a lot happier, because you will be able to live the life you want to live.

Which, ultimately, is what money is really for.