CFI Blog

Numbers are Necessary, But Not Sufficient

“Dear Math,

Please grow up and solve your own problems. I’m tired of solving them for you.”

My soon-to-be wife took a leap of faith in moving from Texas to Virginia after we’d become engaged. Between Christmas and New Year’s, her family loaded her stuff up in a U-Haul, I flew down, and we drove back to Virginia through one of the worst ice storms Arkansas had ever encountered.

Being a typical male, I unpacked her electronics and set them up first. She had a computer, and on that computer was a program I’d never seen: Microsoft Money. Since I’d already had to come clean about my profligate spending habits as a bachelor, I was ready to go to the other extreme and micromanage every penny that came our way. I went to work connecting bank accounts, entering in data, and starting tracking. The only thing missing was the little green visor.

One of the nifty features of the program was a retirement projector. It took your current spending, asked a few questions, and then projected out whether or not you’d run out of money before you ran out of heartbeats. While it wasn’t the most complex program in existence, it did a good job of giving you a ballpark estimate of how much you needed to save to retire when you wanted and with whatever spending level you wanted.

However, knowing the math is what is called a necessary but not sufficient condition for success.

Math is necessary. You have to do the basics: add, subtract, multiply, divide. Anyone who uses the excuse “math is hard” for not getting the simple part of personal finance right is being one thing.


Yes, lazy. It’s not hard to balance your checkbook. It’s not hard to calculate how much you spend. It’s all simple math. The financial planning industry likes to pretend that there’s some sort of voodoo witchcraft involved, using terms like alpha, beta, gamma, mu, and their friends to confuse you, make it seem complicated, and to justify high fees.

Don’t fall for the smokescreen.

However, basic math isn’t enough. You can know the math cold and fail.


Because you never actually take action and transform the projections into reality.

Standing in the way between you and that future you project out is Monkey Brain. Monkey Brain, for those of you who are new here, is what I call your limbic system. There are two main parts of your brain: the prefrontal cortex, which is responsible for actual thinking and higher level intelligence and what makes us different from the rest of the animals in the animal kingdom, and the limbic system, which is the part of the brain that we share with our simian counterparts. The limbic system is what makes us run away from woolly mammoths and jump when we hear the crack of thunder. It kept us alive when we were living in caves, and since our survival was so questionable back then, all it cares about is the immediate future.

Monkey Brain is inherently lazy. He wants gratification, and he wants it now, with as little effort as possible to get there. That part about having to delay gratification and spending less than you make as part of the numbers exercise isn’t going to work with Monkey Brain, and he’s going to do everything in his power to make sure that you don’t actually go forward with your plan.

He’ll tell you things like: “NUMBERS HARD. GETTING 183” FLAT SCREEN TV NO BRAINER.”

Is this your story?

numbers for social security

And after a little haggling back and forth between your limbic system and your prefrontal cortex, it’ll sound like this to you: “OK. We’ll buy that TV. But just this one time. No more! We have a plan to stick to!”

Next month, it’ll be a new toy, and same set of excuses.

Occasionally, you’ll think back on some of your purchases and have a Tommy Boy (#aff) moment: “Oh! That’s gonna leave a mark!”

“But, it’ll be fine,” you’ll console yourself, “I have a plan.”

One day, a dawning realization will strike you. You may have had a plan, but you never acted on it. You’ll be way behind where you’re supposed to be at this point. Even Monkey Brain will get in on the act, stricken by fear of images of you living under a bridge eating cat food. He’ll hit the panic button and tell you that there’s one way to get back on track.

His suggestion won’t involve belt tightening and knuckling down. It won’t involve a second job. It won’t involve hocking all of your unnecessary junk on eBay.

It will involve the stock market.

He’ll tell you that he heard a tip from the brother of the guy sitting next to the guy in the back seat of the bus, and it’s a sure fire way to quintuple your money overnight. Pork snout futures are the “in” thing! They’re a “can’t miss” investment!

In a fit of desperation, he’ll convince you to make the investing equivalent of putting all of your money on Red 35 on the roulette table (astute readers will realize the fallacy of this bet).

And you’ll be back at $0. You’ll have to recalculate the numbers to reflect the new reality. It won’t be as pretty or as rosy as the last time.

But at least you’ll have a plan.

What most of us seem to miss is that, while the numbers are important, they’re not the solution. You can obsess over whether or not you should save $400 per month or $401 per month while actually saving $0, but it’s easier to look at numbers and look at numbers and look at numbers again, do nothing, and say “I can’t do this because math is hard!”

No. Math is not hard. Behavior is hard.

It takes commitment. It takes dedication. It takes visualization. It takes purpose.

Numbers themselves do not have a raison d’être. 53 or 1 million isn’t going to inspire you to take action any more than randomly chosen words out of the dictionary. Instead, picture what your retirement will look like. Whenever you face temptation to stray from the path, use that picture to reinforce your desire to stick to the numbers.

Otherwise, you will find yourself in a downward spiral of justifications and rationalizations.

Planning is easy. Executing is hard. But, finding yourself at retirement age with only Social Security to count on is worse.

Author Profile

John Davis
John Davis is a nationally recognized expert on credit reporting, credit scoring, and identity theft. He has written four books about his expertise in the field and has been featured extensively in numerous media outlets such as The Wall Street Journal, The Washington Post, CNN, CBS News, CNBC, Fox Business, and many more. With over 20 years of experience helping consumers understand their credit and identity protection rights, John is passionate about empowering people to take control of their finances. He works with financial institutions to develop consumer-friendly policies that promote financial literacy and responsible borrowing habits.

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