← My Financial JourneyChapter 14

Will it last?

A calculator that grows your savings by an average every year gives one confident answer, and it is wrong in the way that matters most. Look at a range of futures instead, read the worst one honestly, and adjust while there is still time.

9 min read·Chapter 14 of 15·Next: Retiring in Korea

The trouble with an average

The simplest retirement calculator takes your savings, assumes they grow by some average every year, and tells you when the money runs out. It gives one answer, to the year. It is also wrong in a way that matters, because markets don't deliver averages — they deliver years, in an order nobody chooses.

Here are two retirees with the same S$500,000, each taking S$40,000 a year to live on. Their markets have exactly the same five returns. Only the order differs:

Same returns, different order
Year	First retiree	Second retiree
1	−20% → S$368,000	+25% → S$575,000
2	−10% → S$295,200	+15% → S$615,250
3	+10% → S$280,720	+10% → S$632,775
4	+15% → S$276,828	−10% → S$533,498
5	+25% → S$296,035	−20% → S$394,798

Same average, nearly S$100,000 apart after five years. The first retiree sold investments to live on while they were down, and those shares were never there for the recovery. Bad years hurt most right after you stop working — exactly when you can do least about them.

Many futures, not one

So instead of one average, play out many possible futures — some kind, some cruel, most in between — and look at the spread. Then read three of them:

Savings in today’s money. The shading is where most futures fall; the lines are three of them.

Worst — a poor run of markets. Most futures do better. Plan around it if you want to sleep well.
Median — the middle one: half the futures do better, half worse.
Best — a strong run. Most futures do worse. Enjoy it if it comes; don't plan on it.

For this couple, the best future lasts past 95. The median runs out in the late 80s; the worst, in the late 70s. That is far more useful than one confident year, because it tells them how much the answer depends on luck.

“Lasts in 81% of futures”

The spread can also be read as one share: in how many of all the futures does the money last to the age you plan to? A page that says 81% is giving the honest version of “am I OK?” — not a promise, a likelihood. For the couple above, with the median running out at 88, the share is under half — which is why the next section matters.

Two things it is not. It is not a grade: 100% usually means you could have spent more. And it is not the chance you will be poor at 90 — it is the chance that this plan, unchanged for thirty years, gets you there. Nobody leaves a plan unchanged for thirty years.

The levers you control

Markets are not yours to choose. These are, and each one moves the whole spread:

Before

Save a little more

Every month saved is a month of growth and a month less to fund. Small, early amounts do a lot.

Before

Retire a year later

One more year of saving, one fewer year to pay for, a year later before the first withdrawal. Often the strongest lever of all.

After

Spend a little less

A smaller need shrinks every year's gap at once — and in a bad market year, spending less is what protects the pot.

After

Turn a home into income

Some countries let a home pay a monthly income for life. Korea's version is in Chapter 15.

On the Retirement page these sit together as Close the gap: move one and every figure updates at once, without changing your plan until you decide to.

Look again once a year

A retirement plan is not a verdict you receive once. Your spending changes, a loan ends, a pension statement arrives, markets have their year. Because the plan is built from your ledger, it moves with your life. Look once a year — the same week you look back at your budget — and adjust a lever before a small gap becomes a large one.

🌅 The big idea

Plan for a range of futures, not an average one — and pull the levers you control while there is time.

Read the worst case, aim for the middle, and look again every year.

Your journey so far

Why should I track my money?You cannot make a good decision about something you cannot see.The simplest financial modelMoney comes in, money moves, money goes out — and you know where you stand.What is a personal ledger?Your financial memory: transactions, accounts, receipts and categories in one record that answers questions later.Understanding your accountsThe containers your financial life lives in — what you hold, what you owe, and how a card really works.Income vs. expenseIn, out, or neither — and why your app should never paint your income red.Did that money leave, or did it just move?One line around your household: moves inside it change nothing, and not everything that crosses it is income or spending.A budget you will actually keepSave first, plan the rest — across the year, not just the month — and watch your pace.Build your first personal financial systemFive decisions, half an hour — a household, a ledger, three accounts, a dozen categories and a small plan.Living in multiple currenciesKeep the original, add the perspective — and never invent a single number that spans them all.Two records, one purchaseThe same purchase arrives twice through different doors. Recognising the pair is what keeps every other number honest.What was this purchase for?Ask whoever knows best, in order — and answer each question once, so the review pile shrinks every month.How much is enough?Start from what you really spend, change only what retirement changes, and count every bill once.Who pays you when the paycheck stops?Pensions, pots and income that carries on — after tax, from the age each one starts, never counted twice.

Will it last?Look at many futures, not one average — and pull the levers you control while there is time.

🌅 Next up · Chapter 15

Retiring in Korea

Every country writes its own pension rules. The first country chapter: 국민연금, 기초연금, 주택연금 and the pots Koreans build — and how each one enters the plan.

Read chapter 15 →

See your own range of futures — from your own ledger.

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