On Friday I went to see The Martian, which is all about how to survive on Mars. (I didn't love it as much as Dan did, but it was entertaining enough.) The movie makes you leave the theater thinking, “Thank god I live on Earth,” but the reality is that many of us can’t survive on Earth, either—not without running water, refrigeration, electricity, and all the other amenities of modern life.

But what if you didn’t have those things? Maybe you get lost while driving. Or an accident interrupts your hike. Maybe your plane crashes and you’re stranded in the middle of nowhere. Or, even scarier, a natural disaster hits and the government abandons you. Could you survive?

Until a few days ago, I certainly didn’t think I could. So I decided to take my own advice and enroll in a wilderness survival class last weekend. It ended up being the best $200 I’ve ever spent.

Along with about 30 other people, I learned some basics on water procurement and filtration, fire starting, shelter building, and wild edibles. I learned that you can eat conifer trees, that sap can extend your match life, and, most thrillingly, that you really can start a fire with two sticks (which is definitely not easy! It involves a bow and some carefully carved tools).

There’s one particular survival story that has stuck with me. A guy took a wrong turn in the middle of winter, ran out of gas, got snowed in, and left his family to go for help. He ended up with severe hypothermia and died, while rescuers found his surviving family in the car.

When I asked my instructors about whether it’s best to stay put or go for help when you're lost, they answered that it really depends on the situation. You just have to be prepared for anything.