“Paper or plastic?” You’ve probably heard this question at the grocery store. Or—if you’re like me—you haven’t, because you brought your own bag.

I used to never bring reusable bags to Trader Joe’s. I’d walk out with four giant paper bags and no plan for what to do with them. They’d get stuffed under the sink until there was literally no room left. I told myself I was saving them to reuse someday… but that day never came.

Once I started bringing my own bags, I realized I’d been doing it the hard way for years.

The average American goes to the grocery store at least once a week. If someone leaves each time with just two plastic bags, that adds up to hundreds of plastic bags a year—for one person. Multiply that by an entire community, and it’s a staggering amount of waste. The good news? It’s completely avoidable. A $3 reusable bag can replace thousands of single-use bags over its lifetime. It reduces plastic waste and frees up space in your trash can—and under your sink.

My trick is simple: I leave my reusable bags in the car after every grocery trip so I never forget them.

I can imagine a future with “bagless” grocery stores—and I think it would be a good one. Or at least a future where stores charge a hefty fee for bags. States like California and Delaware already do this, and it works. I grew up in California and saw first-hand how it influences people to bring their own bag. If Utah adopted a similar policy, we’d likely see the same shift.

So next time you head to the store, bring your own bag. It’s a small habit that makes a big difference.

By Sean McCarthy