For the past several years, I’ve been one of the loudest advocates for Coast FIRE.

I genuinely believe it can change people’s lives.

The idea is simple but powerful: save and invest aggressively early on so your retirement investments can grow on their own later, allowing you to focus less on maximizing income and more on building a life you actually enjoy.

For many people, Coast FIRE creates breathing room. It can reduce stress, unlock flexibility, and help you prioritize family, health, and fulfillment long before traditional retirement age.

But there’s a catch.

If the math is wrong, or your life changes dramatically, Coast FIRE can create a false sense of security.

That’s why I invited Bo Hanson from The Money Guy Show onto the podcast. Bo is the co-host of one of the most respected personal finance shows in the country and co-founder of Abound Wealth Management, an RIA with more than $1 billion under management.

And while Bo doesn’t dislike Coast FIRE at all, he does think people need to approach it realistically.

Why Coast FIRE Is So Appealing

Bo immediately understood why Coast FIRE resonates with so many people.

“What I love about Coast FIRE,” he told me, “is basically it’s saying, if I can endure some pain, if I can have this high savings rate, once I hit that goal, then I can take my foot off the gas pedal.”

That’s exactly what drew me to it years ago.

I remember seeing those investing charts showing that someone who invested heavily in their 20s could potentially stop investing decades earlier than someone who started later. That idea fascinated me because, honestly, I didn’t love my corporate job.

At the time, I felt stuck. I had built a strong income, but I also felt trapped by the lifestyle attached to it. Coast FIRE felt like a path toward freedom.

And for many married professionals experiencing burnout, that’s the attraction. Coast FIRE says maybe you don’t need to grind forever. Maybe you can work less, change careers, or reclaim your time earlier than you thought.

But Bo warned that excitement can lead people to overlook the details.

The Biggest Coast FIRE Mistake: Unrealistic Math

According to Bo, the biggest problem he sees is overly optimistic assumptions.

People get excited about the “coast” part but underestimate the burden required to get there and sustain it.

“The quality of the output,” Bo explained, “is very much dependent upon the quality of the inputs.”

In other words, if your assumptions are flawed, your Coast FIRE plan may not hold up in real life.

One of the biggest issues is lifestyle inflation.

A single 26-year-old might believe they can comfortably live on $40,000 per year forever. But then life changes.

Marriage.
Kids.
Moving to a better neighborhood.
Travel.
Healthcare.
College savings.

Bo shared how dramatically his own expenses changed after marriage and children. “My household burn rate changed,” he joked. “I’m not going to say who the culprit was.”

That lifestyle growth is normal, but it can break a Coast FIRE plan if it isn’t anticipated.

This is especially important for married couples. I learned this personally when I started aggressively pursuing financial independence without fully communicating my plans to my wife. I had spreadsheets and timelines in my head, but I wasn’t bringing her into the process.

That caused real tension in our marriage.

Eventually, we went to marriage counseling, and honestly, it became one of the best things we ever did for our relationship. It forced us to communicate about our goals, values, and what we actually wanted our life to look like.

Today, we’re far more aligned because we regularly talk about our finances and future together.

That alignment matters tremendously when pursuing something like Coast FIRE.

Conservative Assumptions Create Better Outcomes

Bo strongly encouraged Coast FIRE enthusiasts to be conservative with their projections.

“No one,” he said, “has ever gotten to retirement and said, man, I just have too much money.”

That line stuck with me.

A lot of Coast FIRE math online assumes long-term stock market returns of 10 percent annually because that’s what the S&P 500 has historically averaged. But Bo cautioned against building plans around overly optimistic projections.

Instead, he prefers using more conservative assumptions in financial planning.

For example, if inflation averages 3 to 4 percent and a diversified portfolio returns around 7 percent annually, your “real” return after inflation may land closer to 3 to 4 percent.

Bo’s philosophy is simple: conservative assumptions create a bigger margin for error and reduce the chances of unpleasant surprises later.

Personally, I tend to lean a bit more optimistic with long-term market assumptions, but I do agree with his broader point: Coast FIRE works best when you regularly revisit your numbers and avoid blindly assuming everything will go perfectly for decades.

Bo also pointed out that many people forget to account for:

• Expense ratios
• Financial advisor fees
• Lower returns from diversified portfolios
• Market volatility
• Inflation uncertainty

Those details matter.

If you’re serious about Coast FIRE, regularly checking your numbers is critical. A tool like our Coast FIRE Calculator can help you revisit assumptions and make adjustments as your life evolves.

And if you’re wondering what realistic Coast FIRE numbers look like at different stages of life, this guide on How to Reach Coast FIRE by Age 30, 40, and 50 is a great place to start.

Your Spending Matters More Than You Think

One of the smartest points Bo made is that your expenses are ultimately what determine whether Coast FIRE works.

You can have a large portfolio, but if your spending expands too aggressively, the numbers stop working.

That’s why understanding your current burn rate is essential.

My wife and I use Monarch Money to track our household spending together. It helps us understand what our real lifestyle costs are, not just what we think they are.

That visibility matters because Coast FIRE is not just an investing equation. It’s a lifestyle equation.

Coast FIRE Without Purpose Can Feel Empty

This was the most important part of my conversation with Bo.

He said many people pursue financial independence because they want to escape something: a stressful job, burnout, or a life that feels misaligned.

But escaping something is not enough.

“You really have to crystallize,” Bo said, “what is it that I’m ultimately moving towards?”

That hit me hard because it mirrors my own journey.

When I first became obsessed with financial independence, I focused almost entirely on leaving my corporate career behind. I thought the goal itself would create happiness.

But the more important question became: what would I actually do with my time?

Bo challenged listeners to think beyond the money itself.

“What about day 100?” he asked. “What about year one? What about year five?”

That’s such an important perspective.

Because if you don’t define purpose, Coast FIRE can become just another number to chase.

And ironically, once you define your purpose, you may realize you can start incorporating pieces of that life today.

Maybe it’s reducing your workload slightly.
Maybe it’s negotiating more flexibility.
Maybe it’s spending more time with your kids now instead of waiting for some distant finish line.

Coast FIRE Still Can Be Incredible

Despite all the cautions, I still love Coast FIRE.

Bo does too.

In fact, he said the couples who pursue it together often end up with incredible stories and shared memories because they intentionally designed their life around common goals.

That’s the key.

Coast FIRE works best when:

• your assumptions are conservative
• your lifestyle expectations are realistic
• your spouse is aligned
• and your purpose is clearly defined

Done thoughtfully, it can absolutely provide peace, flexibility, and freedom long before traditional retirement.

And if your goal is to use Coast FIRE to create more flexibility today, like a 3-day workweek or a more intentional family life, that’s exactly why I wrote Own Your Time. You can learn more about it here: Own Your Time.

Because financial independence is not really about escaping work.

It’s about building a life you don’t feel the need to escape from.