One of my favorite insights into human nature comes from Gretchen Rubin, the author of The Happiness Project and a bunch of other great self improvement / personal development books.

Rubin says people tend to be either over-buyers or under-buyers.

Over-buyers like to stock up and plan ahead. Their shopping habits are motivated by the fear that they might run out of something.

Under-buyers don’t like to buy things until they need them. Their shopping habits are motivated by the fear is that they might waste money or time buying and storing things they don’t need.

I’m an under-buyer. I find it hard to wrap my head around the idea of buying things we don’t need yet. I hate having to throw out spoiled food and don’t like the feeling when cupboards are overflowing to the point that it’s hard to find anything.

But under-buying has its problems. Underbuyers tend to make a lot of late-night trips to the drug store, according to Rubin.

My biggest personal under-buying challenge is that I don’t like to fill up the tank on my car too early. I hate stopping for gas and I’d like to do it as seldom as possible. So if I can time it so my tank is nearly empty — BOOM! — fewer stops at the gas station and more time for me!

But it never quit works out that way. Imagine being a few miles from the nearest gas station and the “Distance to Empty” display on your car is already at zero. I’ve been there. More than once. At other times, I’ve been late for appointments or meetings because I’ve had to stop for gas on the way.

It’s because of stories like this that over-buyers have trouble understanding under-buyers like me.

But over-buyers create their own stress, Rubin says:

Over-buyers feel stressed because they’re hemmed in by stuff. They often don’t have enough storage space for everything they’ve bought, or they can’t find what they have. They feel oppressed by the number of errands they believe they need to do, and by the waste and clutter often created by their over-buying.

The middle-ground — somewhere between overbuying and underbuying — is the best approach.

As part of my journey to be happy, healthy, connected, organized and inspired, I’m trying to do little things that can make a big difference in my life.

One example: I’m trying to buy gas before I need it. My goal is no longer to get gas after I get below 50 kilometers to empty, but before I get to 100. I’ve done this the last few times I’ve filled up the tank, and I must admit, it’s making a big difference in driving-related stress!

What about you? Are you an under-buyer or an over-buyer? Do you feel your shopping tendencies give you any stress?