The Jar That Shapes Your Kid's Financial Future
- Will Rainey
- Jun 27
- 5 min read
There is an amazing video of a philosophy professor teaching his class an important life lesson in the most visual way. And whilst he wasn't teaching about money, I strongly believe the same visual can help your kids understand how to manage their money as they grow up. Let me explain.
The Professor and the Jar
The professor enters the classroom and places a large empty jar on his desk. He then pulls out a box of golf balls and starts dropping them in, one by one, until no more will fit. He turns to the class.
"Is the jar full?"
"Yes!" the students reply.
The professor then pulls out a bag of small pebbles and pours them into the jar. They tumble into the gaps between the golf balls, settling neatly into every space.
"How about now, is the jar full?"
"Yes!" say the students again.
The professor reaches under the desk and pulls out a bag of sand, pouring it slowly into the jar. It fills every remaining gap between the pebbles.
"Is the jar full now?"
The students laugh. "Yes!"
Then the professor pulls out a bottle of beer, though depending on which version of the video you watch, this is sometimes coffee, which is probably more appropriate for a classroom!, and pours it in. It absorbs into the sand completely.
Now the jar is full.
A Happier Life
The professor then says:
"I want you to recognise that the jar represents your life"
He goes on to explain that the golf balls are the most important things in life, family, friends, health, passions. The pebbles are the essentials, housing, food, transport. The sand is the small stuff. And the beer? That's pure fun.
Then comes the most important part:
"If you had filled the jar with sand first, you wouldn't have been able to fit the golf balls or the pebbles in."
And that, he explains, is exactly what most people do with their time. They fill their days with small stuff, emails, errands, scrolling, and find there's no room left for the things that actually matter. Family. Health. Friendships. The golf balls get squeezed out by the sand. This means that the small stuff takes away from what really matters and that can have a big impact on your happiness.
Essentially, for a happy life, set your priorities:
"Take care of the golf balls first"
You can watch the video here:
It's a powerful wake-up call about priorities. And the first time I watched it, I couldn't stop thinking about how this also applies to how people manange their money.
The Same Lesson - But for Your Kid's Budget
I believe this is one of the most powerful visuals you can use to help kids understand the importance of budgeting.
Here's how I reframe it:
The golf balls are savings and investments, the non-negotiables. The money that needs to go in first, before anything else, because if it doesn't go in first it never goes in at all.
The pebbles are essential spending, bills, food, housing, transport. The things that matter and need to be covered, but which can settle around the golf balls, if the golf balls are already in place.
The sand is lifestyle spending, coffees, meals out, clothes, subscriptions, holidays. Not bad things at all, but the stuff that expands to fill whatever space is left. And if you pour it in first, there's no room for anything else.
Why Most Adults Fill the Jar in the Wrong Order
Most adults budget backwards. They spend on lifestyle, cover the essentials, and save whatever happens to be left over, which is usually very little, sometimes nothing.
The jar looks full. But the golf balls never went in.
What makes this even harder is that the world is set up to encourage sand-first thinking. Advertising, social media, and social pressure all push lifestyle spending to the front of the queue. And as the jar gets bigger, as people earn more, they don't add more golf balls. They simply pour in more sand.
This is the trap that catches so many adults who earn good salaries but have very little to show for it. The jar was never too small. The order was just wrong.
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Helping Your Kids Fill the Jar in the Right Order
Showing your kids the jar lesson is one of the most powerful ways to help them understand the importance of budgeting and 'saving before you spend' (the first rule of wealth).
This is one of the reasons I encourage my daughters to save at least 10% of every bit of money they receive, whether it's pocket money, birthday money, or money earned from odd jobs. The amount isn't the point at this stage. The habit is. I want them to put the golf balls in first, every single time, so that it becomes second nature long before the jars get bigger.
When you fill the jar in the right order, you can actually fit more in. Savings generate returns. Investments grow. The golf balls create more room for pebbles and sand over time, not less.
Getting the order right doesn't mean sacrificing the fun stuff. It means the fun stuff is actually sustainable.
(I'll also mention that when I did this experiment with my own kids, I swapped the beer for popcorn and sweets. Much more effective.)
Try It at Home
I'd encourage you to show your kids the video, or better still, grab a jar and do your own version. Fill it with sand first and ask them if the golf balls fit. Then empty it, start with the golf balls, and watch everything settle into place.
Ask them: which way would you fill your jar?
Then tell them that's exactly the question to ask every time they receive money.
I know the jar lesson will stick with my kids for a long time. I hope it does the same for yours.
Thanks for reading,
Will
👉 What to read next:
Rich Kids vs Wealthy Kids (essential)
Grandpa's Fortune Fables: stories that teach kids more about money than most adults know
