Every case here is one piece of the same investigation: how money actually works, and how to make it work for you. Crack them in order or jump around — each file ends with a knowledge check. Close it, and the case is solved.
Case files are yours to share — the whole thing is one file. Working a case with someone you trust makes it stick.
Every investigation starts with the basics everything else rests on: what actually lands in your account, where it goes, and the reserve that keeps one bad week from unraveling everything.
The number on the offer letter is the gross. What actually reaches you is the net — after taxes and deductions take their cut. Closing that gap in your head is the first case. Drag your pay and watch where it goes.
A budget isn't a cage — it's a paper trail for the take-home above, decided on purpose instead of by accident. A common starting split is 50/30/20: half to needs, a third to wants, a fifth to saving and debt. Adjust to real life; high rent shifts the mix.
Based on your take-home of $0/mo from Exhibit A. That 20% save slice is what feeds Cases 03 and 04.
An emergency fund is cash for the surprises — a car repair, a job gap, a medical bill. It's what keeps one bad week from turning into credit-card debt, or forcing you to sell investments at the worst possible time. Aim for 3–6 months of essential expenses, kept in high-yield savings.
Tax math is a simplified estimate (2025 single-filer standard deduction and brackets, 7.65% FICA, flat state rate); it ignores pre-tax deductions, credits, and local taxes. Real paychecks vary. Not personalized advice.
Debt is the one adversary that works while you sleep — interest never takes a night off. This case is about seeing exactly how it works against you, the two proven ways to shake it, and keeping a clean record so it never has leverage on you.
The same force that grows your investments runs in reverse on debt. Credit cards are the worst offenders, and the minimum payment is engineered to keep the meter running for years. Work the dials and watch the trap.
The move is always the same: pay the minimum on everything, then throw every spare dollar at one target. Two schools disagree on which target. Here are the same example debts run both ways — adjust your extra payment and flip between them.
Your credit score is the record lenders pull before they trust you with a car loan or a lease — and a good one saves you thousands in interest over a lifetime. Here's roughly what it's made of (the exact weights vary by scoring model).
The top two — paying on time and keeping balances low — are two-thirds of the whole score, and both are entirely in your control.
Payoff and interest figures are simplified estimates (fixed monthly rate; illustrative minimum-payment and example-debt figures); real cards vary in how minimums and interest are calculated. Not personalized advice.
Not all savings are the same. Money you need soon and money you need in decades play by completely different rules — and mixing them up is one of the most common ways people get burned.
Every goal goes into one of two vaults, decided by one question: when do I need this money?
Somewhere safe and boring — a high-yield savings or money market account. It won't grow much, and that's the point: it can't drop right before you need it.
Invested for growth — index funds in a Roth IRA or 401(k). It swings year to year, but it has decades to ride those swings out and compound.
A sinking fund is a named savings bucket you fill a little at a time for a known goal, so it doesn't wreck your month when it arrives. One per goal.
Say the deposit + first month runs ~$3,000, due in 10 months. That's not "hope it works out" — it's $300 a month into a labeled account, starting now. Boring, automatic, done. The tool below runs any goal for you.
Name a goal, set the amount and the deadline — see what it takes, and where the money should live.
The whole case in one line: the sooner you need it, the safer it has to sit. A market that's your best friend over 30 years is a menace over 8 months. Short-vault money stays in savings; only long-vault money gets invested.
A starting point, not personalized financial advice; figures are illustrative and rates change over time. Talk to your dad (or a professional) when real money's on the line.
This is the case that pays for the rest of your life. You've got the one thing money can't buy back — time — and more of it than anyone. Here's how to use it.
Drag the sliders. Watch what a small monthly habit becomes by 65 — and what waiting 10 years costs. Even $25/month started now beats big money started after grad school.
Once you're working, if your employer matches what you put in, that's an instant 50–100% return. Contribute enough to get all of it.
Free moneyYour own account. You put in money you've already been taxed on, and it all comes out tax-free at retirement — especially attractive early in your career, when your rate may be lower than it will be later. One catch: you need earned income from a job to contribute.
Best for your ageAs you earn more, raise what you invest — work toward saving ~15% of income. Build up to it; don't stress it at 20.
Level up"Roth IRA or index fund?" is a trick question — like "backpack or textbooks?" The Roth is the backpack. Index funds go in it.
Pick a box → put investments inside → let time work.
Tap each. Most young investors put nearly everything in a low-cost index fund and get on with life.
That smooth curve up top is a simplification. Real markets jump 50% one year and drop 37% the next. Here's every 30-year stretch in history at $100/month — drag to pick your start year.
A crash feels like an emergency. It's the only time stocks go on discount. The people who get hurt aren't the ones who live through a crash — they're the ones who sell. Real numbers, 2008, on $10,000 already invested:
That automatic $25 or $100 every month buys more shares when prices crash — you scoop the discount without guessing the bottom, which even pros get wrong.
3–6 months of expenses in plain savings. That's what keeps a job loss or car repair from ever forcing you to sell at the bottom.
Uses S&P 500 total returns (dividends reinvested), 1926–2025; real life shaves off fees and taxes. The 7% is illustrative. History isn't a guarantee. Not personalized advice.
Building a case is only half of it — the other half is making sure no one can take it from you. This case is your defenses: the coverage you actually need, the life-insurance con to see through, and the paperwork and habits that keep thieves out.
Insurance has one job: take a risk that could wipe you out and hand it to someone else for a small monthly fee. You don't insure the small stuff — you insure the catastrophes. Flip your situation on and see what actually applies to you.
If someone does depend on your income, life insurance matters — but the industry pushes the expensive kind hard because it pays big commissions. Here's the honest comparison.
There's an insurance product for almost any fear, and most exist because they're profitable for the seller — the risk is small or the payout is capped. Run every offer through one test: would this loss actually wipe me out, and could I not cover it myself? If the answer is no, skip it and self-insure with your emergency fund.
Two quiet things that protect everything you're building.
The person you name as beneficiary on a 401(k), IRA, or life-insurance policy overrides your will. Set them when you open the account, and update them after any big life change — it takes two minutes and prevents real messes.
And lock down your identity — most of these are free and take minutes:
General education, not insurance or financial advice; coverage needs and costs vary by person, state, and insurer. Sample premiums are rough illustrations. Not personalized advice.
The last stretch is the long game: how taxes actually work (so you stop fearing a raise), how to grow the one number that matters most — your income — and how to point all of it at a life you actually want.
The most common tax myth is that crossing into a new bracket taxes your whole income at the higher rate. It doesn't. Brackets are like buckets that fill in order — only the dollars in the top bucket get the top rate. Drag your income and watch it fill.
Budgeting matters, but your spending can only shrink to zero. Your income has no ceiling — raises, new skills, switching jobs, a side gig. And a raise you invest instead of absorb into your lifestyle compounds like everything else. Drag a raise you'd bank each month:
Every case before this one was mechanics. This is the reason for them. Money is only useful for what it buys you — and that's different for everyone. What is it really for, to you? Tap what fits.
Federal tax figures use 2025 single-filer brackets and the standard deduction, federal only; they ignore state tax, credits, and other deductions. Illustrative, not personalized advice.