By Mark Lebetkin
The Active Times

What do you do when survival is not guaranteed?

You’re lost, stranded, injured miles from civilization -- if you even know what direction civilization is. Chances are you haven't taken a survival course, and all you've got to fall back on are your wits and fragments of received wisdom that you’ve gleaned from TV, movies and maybe a magazine article or two.

The sun's going down, and your stomach starts growling, and you think, "Maybe I should find some berries for dinner" -- you’re pretty sure you know which ones are edible. Or it’s been a couple days and you remember an episode of Man vs. Wild where Bear Grylls chows down on a raw grub and think “I might just be hungry enough…”

Or, say you've hiked to the bottom of a canyon and realize you don’t know how to get out and your water's running low. "I should make this last,” you think before your mind turns to an old John Wayne movie where he squeezes clear liquid from the pulp of a barrel cactus.

Ask a survival expert, though, and he or she will likely tell you none of these things is a good idea.

For just about any survival situation, there's a wealth of knowledge out there, and a lot of it's bad. Often things aren't helped by the burgeoning number of survival reality shows, which are designed to entertain rather than to educate.

"I've worked on these reality shows," says Tony Nester, an expert on desert survival and head of Ancient Pathways, an outdoor survival and bushcraft school based in Flagstaff, Arizona. "They're heavily scripted and there’s always a support crew within twenty feet, twenty-four seven."

Click here for survival schools
12 Survival Schools That Could Save Your Life

As a teacher, Nester constantly finds himself correcting his student’s misconceptions about what do in survival situations. For example, students often come to his survival courses and want to learn right away how to make fire by rubbing sticks together.

"Hey, there’s no greater joy than sitting next to a fire that you made the old way,” says Nester. "But that’s not what I want to do when I have an injured shoulder and the sun’s going down and it’s getting cold."

One of Nester’s favorite examples is the solar still, a device one can make -- given the right materials -- to collect and distill water. Grylls once made one on his show to demonstrate desert survival, and students ask Nester how to do it themselves. Nester teaches his students the method’s fatal flaw by having them make their own. (Hint: digging a hole in desert heat is no easy task.)

Nester emphasizes that there's a difference between "survival" -- living long enough to be rescued -- and "bushcraft" -- the art of living outdoors -- which people often miss, or are unaware of.

People get hung up on the idea of the survival hero, he says, and don’t realize that most survival situations are much more mundane. “80 percent of people who get lost in the U.S. and North America are day hikers. They have a mentality, when they’re at home, they think ‘I’ll just go for a day hike or mountain bike. I’m only going for two hours -- what’s the worst that can happen?'"

Tim Smith, the founder of Jack Mountain Bushcraft School in the Maine North Woods, is also quick to teach his students this distinction. “Survival is very romanticized,” says Smith. "It's not about being the toughest or most experienced; it’s about keeping out of those situations."

Survival, according to Nester, Smith and Shane Hobel of Mountain Scout Survival School in upstate New York, is a matter of getting your priorities straight. (Shelter, water, and a clear mind are at the top of your list, by the way.) We asked them to share some of the most persistent survival myths they encounter, and their corrections.

For the complete list of Survival Myths, go to TheActiveTimes.com.

More Stories from The Active Times:
-- The 12 Best Rugged, Reliable Flashlights
-- 3 Ways to Rent Camping Gear
-- How to Pack a First Aid Kit
-- 13 Sports That Could Kill You