Week 5: The Two Choices You're Making at Eighteen That Most Adults Wish They Could Take Back

We've talked about the real cost of college. We've talked about student loans and what you're really signing when you sign that paperwork. Today we close out the college-bound portion of the series with two decisions that don't get nearly as much attention as they deserve.

The first is what you do with credit and credit cards as you move into adulthood. The second is how you choose your major and the career path that comes with it.

Both of these decisions are going to be presented to you as small ones. Both of them will follow you for decades. And both of them are decisions that, when made wrong, become some of the most common things adults tell me they wish they could go back and redo.

Let's make sure you don't have to.

Why Your Credit Score Matters at 18 (And Most People Don't Realize It Until 28)

A credit score is a three-digit number that tells lenders how likely you are to pay back money you borrow. It runs from about 300 to 850. The higher, the better. That much you've probably heard.

What you probably haven't been told is everything that score touches in your adult life. Your credit score determines whether you get approved for an apartment. It determines what your car insurance costs — yes, really, your insurance premium is partly tied to your credit. It determines whether you can rent a car. It determines whether you get the job you applied for, because more employers run credit checks than people realize. It determines the interest rate you'll pay on your first mortgage, which over the course of a thirty-year loan can mean the difference between an extra $50,000 or $150,000 paid in interest on the exact same house.

That's the world you walk into at 18. And the worst part is, you walk into it with no credit history at all. Not bad credit. No credit. Which is almost as much of a problem.

Building credit is something you do on purpose, over time, starting young. The students who graduate college at 22 with no credit history end up scrambling for their first apartment, their first car, and their first real job, because the system was set up to reward people who started building credit earlier — and they weren't told.

You can be the one who was told.

How to Build Credit Without Falling Into the Trap

Here's the catch. The way you build credit is by borrowing money and paying it back on time. Which means you have to interact with the system that has been very, very good at trapping young people for decades.

The right way to do this, at 17 or 18, is to start small and start safe. The easiest path is to have a parent add you as an authorized user on one of their credit cards. You don't have to actually use the card — sometimes you don't even have to be physically given the card. Just being added to their account can put their credit history on your file, which gives you a head start most of your friends won't have.

If that's not an option, the next step is to get your own card — but a starter card. A student credit card or a secured credit card with a low limit. Something with a $300 or $500 limit, not a $5,000 limit. Then you use it for one small recurring expense — a subscription, a tank of gas, your phone bill — and you pay it off in full, every single month, without ever carrying a balance.

That last part is the entire game. Pay the whole balance every month. If you do, you owe zero interest, you build credit history, and the card works for you. If you carry a balance, the average credit card interest rate is around 22 percent, which is a number designed to keep you in debt for years.

A credit card is a tool. Used right, it builds your financial life. Used wrong, it destroys it. There is no in-between.

Now the Other Decision: Your Major

Now let's shift to the second big choice. The one that's going to determine, more than almost anything else, what your twenties and thirties actually look like.

Your major.

I'm going to be direct with you here. The advice "follow your passion" is one of the most well-intentioned and most financially damaging pieces of advice ever given to eighteen-year-olds. Not because passion doesn't matter — it absolutely does — but because passion alone doesn't pay your student loans. Passion alone doesn't pay your rent. Passion alone doesn't fund the life you actually want to live in your thirties.

The right move isn't to pick passion. It's also not to pick the highest-paying major you can stand for the money. The right move is the one almost nobody helps eighteen-year-olds do — pick passion plus a plan. Pick something you actually care about, and then pick a version of that thing that the world is willing to pay for.

You like writing? Great. There's a version of that where you're a freelance poet making $18,000 a year, and there's a version where you're a copywriter in tech making $140,000. Same skill set. Different applications. Different financial outcomes.

You like helping people? Beautiful. There's a version where you're an entry-level nonprofit worker making $35,000 with $80,000 in student debt. And there's a version where you're a nurse practitioner making $130,000 with the same desire to help people and a fraction of the financial stress.

The lie nobody calls out is the idea that you have to choose between meaning and money. You don't. You have to think about both. And eighteen is when that thinking starts, not twenty-eight when the bill comes due.

How to Choose a Major Like an Investor

Here's what choosing a major like an investor actually looks like.

You start with what you're interested in. Honestly interested in — not what your parents want, not what sounds impressive at parties. What you'd actually pick up a book about voluntarily.

Then you research. You look at what careers that major leads to. You look at what those careers actually pay. Not the dream number — the realistic median for someone five years in. You look at job growth projections. You look at where those jobs are located, because some fields concentrate in expensive cities, and a $70,000 salary in San Francisco is not the same as a $70,000 salary in Des Moines.

Then you compare. Take the projected starting salary for that career. Stack it against the total college cost you'd be taking on to get there. If the salary covers the debt with room to live, save, and invest, the major makes financial sense. If it doesn't, you need a different version of the major, a cheaper school to pursue it at, or a different path entirely.

This isn't selling out. This is being honest with yourself before the system gets a chance to be dishonest with you. Plenty of people are doing meaningful, fulfilling work in fields they love and making good money. The trick is knowing both halves of that equation matter before you choose, not after.

What You Actually Do This Week

If you're seventeen or eighteen, two moves.

First, the credit piece. Talk to your parent about being added as an authorized user on a card they manage well. If that's not on the table, look into a starter student card with a low limit. Set it up to handle one small monthly expense automatically, and set up autopay to clear the balance in full every month. Then forget about it. The credit builds quietly in the background while you live your life.

Second, the major piece. Take a Saturday morning. Sit down with a piece of paper. Write down three or four majors you're actually drawn to. For each one, look up the careers it leads to, the median salary five years in, the job market in your region, and the typical debt load students take on to enter that field. Then compare. Be honest with yourself about what you're really signing up for. A choice made with eyes open at 18 beats a course correction at 25 every single time.

For the Parent or Guardian Reading This

If you're the parent, your job here is to do two things. First, help them build credit early without setting them up for a fall. If you can, add them as an authorized user on a card you manage responsibly. It costs you nothing and gives them a head start most of their peers will not have. If your own credit isn't where you want it to be, be honest about that — there are still other paths, and the conversation itself is the lesson.

Second, help them think about the major like an investor without crushing the passion piece. This is the harder conversation. It's tempting to lean too hard one way and tell them money is everything, or to lean the other way and tell them to follow their heart without questioning it. Neither is right. The truth is in the middle — passion is essential because it sustains effort over decades, and pragmatism is essential because passion doesn't pay loan servicers. Hold both. Make them hold both.

And run the actual numbers with them. Look up real starting salaries. Look up real debt loads. Make abstract feelings concrete with arithmetic. Eighteen-year-olds can handle hard numbers. What they can't handle is making a hundred-thousand-dollar decision based on vibes alone.

The Setup Lasts a Decade

The next four years of college are not, despite how they're marketed, the most important years of your life. They're the setup years. The actual life — the career, the family, the wealth, the freedom — gets built in your twenties and thirties on the foundation you're laying right now.

Build credit on purpose. Choose a major with both halves of the equation in mind. Walk into adulthood with your eyes open. The kids who do this don't end up "behind." They end up years ahead, while the kids who didn't think about any of it spend their twenties recovering from decisions they didn't know they were making.

That's the entire summer series so far, in one sentence. You don't get behind by what life does to you. You get behind by what you don't know to plan for.

Next week we shift into the new grad portion of the series. We're starting with the negotiation conversation almost no one has — and the reason most twenty-two-year-olds walk into HR and accept a number that isn't actually the number.

See you next week.