Wouldn't it be/have been nice to retire at age 29? Oh, by the way, with $54 million dollars? That's what New England Patriots 9-year NFL "veteran" and Tom Brady fave-target, Rob Gronkowski, is doing. The future hall of fame tight end called it quits on Sunday.

Gronkowski is known as a big party guy, seen in viral in videos without his shirt on, guzzling who-knows-what. So I was admittedly a bit surprised when I heard that Gronkowski tackled his finances with the same discipline that he famously used in training, recovery (from multiple serious injuries), and on the field. The New England NFL'er has played a simple, but powerful financial strategy.

He's been living off his endorsements only, and bankrolling his entire salary, like fellow NFL stars Marshawn Lynch and Saquon Barkley are doing. Not that Gronkowski is exactly forced to eat Kibbles 'n Bits, with endorsement deals with such brands as Tide Pods, Body Armor SuperDrink, Dunkin' Donuts, and beef jerky company Oberto. 

As Gronkowski told Business Insider last year:

Keep it easy, simple. Get what you need to be comfortable, save the extra. It's a short career here in the league. The average is about three to four years, and when it's done, it's done. Be simple, manage it safe, so when it's done you've got a little base, a little foundation to live off.

How you can apply Gronkowski's strategy (if not money) to your own situation.

It boils down to three steps.

1. Challenge your assumption of what it takes (and means) to be comfortable.

While Gronkowski does have what he calls a few "broke habits" (living in certain ways like you're broke, like he does with his clothes), no one said to save money you have to live like a pauper. But it does require a mindset shift of what "comfortable" really is.

Before I made the leap from corporate to entrepreneurialism, my wife and I decided I'd do so on two financial conditions. We'd trade down our lifestyle a bit and lower our expenses--both so we could more easily build a solid financial buffer if something went wrong. We've learned to live without a lot of things we thought we needed--and we're happier.

2. Create two streams of income and bank the bigger one.

This is particularly relevant for entrepreneurs. Gronkowski lives off his smaller stream of income, sharing this strategy with former late night talk show icon Jay Leno. Leno famously lives off the money he makes in standup and hasn't touched any of his money from his Tonight Show gig. He hosted the program for 17 years, with annual salary touching $30 million/year.

Now, I know what you're thinking. "Yea, I could live off my second stream of income if it was millions a year like Gronkowski's and Leno's". True, but that's not the point.

As long as your second stream of income is reasonable enough and fits your reframed definition of comfortable (see point one), the same approach is just as relevant for you. My wife and I have our entire financial plan built on living off of the profit from our entrepreneurial venture, without touching the much larger corporate nest egg we built.

3. Splurge a little to save a lot.

Both Gronkowski, Leno, and yes, my wife and I (the audacity, to put us in the same circle!) all made purchases as a reward for hard work and to incentivize future saving.

Gronkowski finally bought a splurge item after his eighth year playing, a diamond encrusted chain, while Leno purchased a serious car collection (remember, the absolutes aren't what counts here). As for me and my wife? Well, if you must know, it was a Mini-Cooper. Just one. And I traded in my Infiniti for it. But it was a splurge because of what it represented--commitment to a new "mini-er", post-corporate life.

When it comes to income, maybe the idea of saving your main stream isn't mainstream yet. But if you apply these principles in your own way, on your own terms and scale, maybe you'll be in the saving hall of fame too.