Here’s a simple thought experiment. If you didn’t have the things you have right now, would you buy them?
Imagine if all your stuff were to disappear right now. But in exchange, you’re given a sum of money equivalent to the value of everything that’s gone and also the option to buy back whatever you want. So the question is, how much of your stuff would you want to buy back? Or rather, what wouldn’t you want to buy back?
As an example, let’s say three things disappeared. A brand new watch you bought for $100, an old pair of sneakers you bought for $100 when it was still new, and a broken beyond repair microwave oven you bought for $100 when it was still new. When those three things disappeared, you were given $95 for the watch, $10 for the sneakers, and $0.05 for the microwave oven. Would you spend $95 to buy back the watch, or $10 for the sneakers, and would you want to get that microwave oven back for $0.05?
Instead of wondering what you should get rid of when decluttering, it’s far easier to just pretend they’re all gone and start from nothing. If you have nothing right now, what would you buy? And if you wouldn’t buy it, why do you still insist on keeping it?