Think back ten years for a moment. How many clothes, pieces of furniture, gadgets, cars, tools, or random little objects did you own back then? Now take a look around your apartment. How much stuff has shown up since? And honestly - how much of it was truly necessary?

If the answer is “a lot,” don’t worry. You’re in good company. Most of us have a natural urge to keep buying new things, and we rarely reach that magical moment when we say, “That’s it. I have everything I need.”

So why does this keep happening? One possible explanation is something called the Diderot Effect.

Denis Diderot was a French philosopher who lived in the 18th century. For most of his life, he was pretty poor. Then, in his early fifties, things changed: Catherine the Great bought his personal library and paid him a generous sum for it.

Suddenly, Diderot had money - not just to survive, but to enjoy life a little.

One of the first things he bought was a beautiful, scarlet dressing gown. And that’s where things got… complicated.

The new robe was gorgeous. Too gorgeous, actually. Compared to it, everything else he owned looked old, shabby, and out of place. The harmony was gone. And that bothered him more than he expected.

So what did he do?

He didn’t return the robe. Instead, he started upgrading everything else.

Out went the old rug - replaced by a luxurious Damascus carpet. A fancy mirror appeared above the fireplace. The straw chair was banished to the hallway and replaced with a leather one. Then came a grandfather clock, bronze sculptures, a wardrobe…

One purchase triggered another. And another. And another.

Diderot later described this whole situation with humor and irony in an essay called “Regrets over an Old Dressing Gown.” Much later, anthropologist Grant McCracken gave this pattern a name: the Diderot Effect.

At its core, the Diderot Effect is about our need for coherence. We like things to “match” - our stuff, our identity, the image we have of ourselves.

That’s why you buy a suit… and suddenly you need a new shirt, tie, and shoes. You buy a dress… and realize your old shoes just won’t do. You get a new bike… then riding gear, a helmet, a lock, a cycling app, and a speedometer feel essential. You replace your sofa… and now the armchairs and dresser look embarrassing. You buy a new TV… and upgrading your internet suddenly feels unavoidable.

Sound familiar?

One “small” purchase quietly rewrites the rules for everything else.

Is shopping the enemy? Not at all.

Managing your money isn’t about extreme minimalism, saying no to every pleasure, or living like a monk. It’s about conscious spending.

The Diderot Effect is just one example of how automatically we react to buying triggers. Researchers know this very well and marketers use that knowledge constantly. Carefully matched products, cozy family scenes in ads, cute babies, beautiful colors, perfect lighting, catchy music, ego-boosting messages… all of it is designed to push us toward impulse purchases.

And that is the real problem.

Impulse buys empty wallets and slowly turns our apartments, garages, and basements into storage units.

First: we buy only when we can afford it. That means no loans or credit for things that aren’t truly necessary. Debt has a sneaky way of draining money long after the excitement of the purchase is gone.

Second: we buy things that genuinely matter to us. That doesn’t mean “buy only the bare essentials.” It means choosing quality, usefulness, and real value over clutter.

We can also consciously spend it on something that will truly improve our quality of life or be an investment in experiences. An interesting trip, a good book, a dream concert, an investment in our own development.

By doing this, we gain twice: we have more space at home and broader horizons in our minds.