Last month, our friends at Rockstar Finance challenged readers to avoid eating or drinking out for an entire week.

As someone who has purchased his lunch on roughly 99% of the working days of his career, I decided to give the challenge a try.

And you know what?

I was successful, and the world didn’t end.

Now I’m not going to claim this challenge was as difficult as climbing Mt. Everest.

The nicest thing I can say about the cafeteria at my office is that it is convenient.

So convenient, I mindlessly purchase at least $50 of their mediocre food almost every week, when I add up five lunches, plus the occasional breakfast, beverage, dessert, or snack.

I don’t want to turn this post into a debate about $5 lattes.

Or, God forbid, avocado toast.

But this simple challenge did get me thinking about the massive impact thousands of tiny decisions can have over the course of a lifetime.

I estimate that I purchase lunch in the cafeteria at my office roughly 220 days a year.

Lunch usually runs between $8 and $9, so at a minimum I spend $10 a day at the cafeteria when I factor in the occasional additional purchases mentioned above.

Meaning I’m spending at least $2,200 a year buying lunch at the cafeteria.

I calculated that I was able to feed myself for about half that price by bringing food from home while participating in the Rockstar Finance challenge.

Meaning I could save around $1,100 a year by packing my lunch every day.

Over the course of a forty year working career, that’s over $44,000!

Before factoring in what could happen if I invested the extra $1,100 each year!

If that $1,100 in annual savings were invested at 5% a year for forty years, the power of compound interest turns it into over $130,000!

Meaning a small change, like bringing my lunch to work every day, rather than hitting the cafeteria, deli, fast food restaurant, food truck, or diner, could literally cut years off of my working career. Or result in over $5,000 a year in extra spending money in retirement, if I decided to work just as long.

At 45-years-old, it’s too late for me to generate that much benefit.

Especially since I don’t plan on working full-time for more than five more years.

But I could still retire with an extra $6,000, simply by brown bagging it until I turn 50.

The point is, over the course of days, weeks, months, years, and decades, small decisions can have an incredible impact on our personal finances.

And sadly, buying lunch almost every weekday for nearly a quarter of a century really hasn’t even been a conscious decision for me. Most days, I haven’t given it a second thought.

It’s just been a habit.

A habit that has probably cost me nearly $50,000 since I started working full-time.

This got me thinking about the possible impact of dozens of other small decisions that have become habits, and the potential impact that changing things, just a tiny bit in the direction of frugality, could have on my quest for financial independence.

Like cutting my shower to five minutes from ten minutes.

Like keeping the temperature of the house a couple degrees warmer in the summer, and a couple degrees colder in the winter.

Like cutting out snail mail, and using free online bill paying on everything possible (sorry Millennials, some of us Gen-X dinosaurs still don’t do this with every bill yet… and don’t tell anyone, but I’ve never used Venmo in my life!).

Like planning shopping trips more intelligently, so Mrs. ROMT and I don’t end up driving to the same store on the same day.

Like canceling the auto-renewal subscriptions for things I don’t use enough to justify the expense.

Some of these decisions will literally save only pennies a day.

But pennies a day, times many decisions, times 365 days a year, times decades, can add up to tens of thousands of dollars!

I am not good at frugality, much less extreme frugality.

I have tended over the course of my lifetime to focus on making sure I got the big financial decisions right, and typically let the small things slide.

It has generally served me well. Our family is in a position where FIRE within the next five years is an achievable goal.

But if I had known about the concept of FIRE 25 years ago, I would probably be financially independent already – assuming I had used that knowledge to make a few simple changes to my spending habits over the years.

I haven’t brought my lunch to work every day since the Rockstar Finance challenge ended.

But I have been bringing lunch two or three times a week since then.

If I am able to do that consistently, I should save over $500 a year.

And hopefully it will also help me avoid eating any more of the cafeteria’s pale gray sloppy joes!

What small changes have you made to your spending habits that add up to big bucks over time?