Don't get carried away. Flickr / Damian Morys

I'm an accountant, and one of my clients has been on a roll.

Their income began to rise significantly about five years ago. One of the first things they did with all of this extra money was to spend it on a very expensive, million-dollar home in an upscale neighborhood.

But that wasn't all. They proceeded to spend approximately $150,000 refurbishing their very expensive, million-dollar home. Now they are stuck with an expensive home, with higher real estate taxes, higher utility bills, and significantly greater maintenance costs.

I had another client who, after a banner year, went out and bought an expensive $100,000 sports car.

Another client of mine, during their high income years, spent nearly $1 million on things they were eventually forced to sell for pennies on the dollar, when they lost their job, in order for their family to survive.

This is called lifestyle creep - increasing your standard of living in order to match your increased income.

Over the course of the five years I spent interviewing 233 wealthy individuals (177 of whom were self-made millionaires) with at least $160,000 in annual gross income and $3.2 million in net assets, as well as 128 people who had less than $35,000 in annual gross income and less than $5,000 in liquid assets, I found that lifestyle creep is a bad habit common among many who suddenly find themselves making more money.

The good habit - I call it the "Rich Habit" - is to forgo the desire to spend your money today and, instead, sock it away into savings and investments that grow in value and provide financial resources that can be used in the future to maintain your standard of living.

That Rich Habit is called delayed gratification. You put off something you want today for something you want tomorrow: financial independence.

Delayed gratification is a habit that must be forged, because instant gratification is hardwired into the DNA of every human.

In the early days of human existence, it was feast or famine. During very rare periods of food abundance, ancient humans would take immediate advantage of this abundance and gorge themselves. Doing so enabled early humans to build up significant stores of fat. When food scarcity returned, early humans were then able to survive by living off those stores of fat accumulated during the periods of food abundance.

This might sound familiar when you look at modern humans' behavior with money: During periods of financial abundance, humans tend to gorge themselves financially, by spending their financial abundance immediately on more expensive homes, exotic sports cars, and/or the latest in technology.

The problem is, once you spend your money, it's gone. When scarcity returns, you are forced to sell your stuff. If the stuff you purchased depreciated in value, you get pennies on the dollar.

One of my oldest and dearest friends explained to me his rule for financial success:

"Same house, same spouse, same car."

There's a lot of wisdom in these words. What they really mean is that no matter what good fortune visits you in life, do not change your standard of living. Don't supersize your life by buying things you really do not need.

Living a modest life and forging the Rich Habit of delayed gratification - putting off what you want today so that you can have something to fall back on in the future - will help you build wealth.

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