The phrase "Be afraid, be very afraid" was a tagline from the 1986 horror flick The Fly. Google the phrase and you'll get about 183 million results for that phrase. But the trick is to be appropriately afraid of the right thing. What people commonly fear is not always what should be causing that spike of adrenaline. Here are some examples:

Are you afraid to fly? You have a 0.00001 percent chance of dying in an airplane crash. On the other hand, the car insurance industry estimates that the average driver will be involved in three or four car crashes in their lifetime and the odds of dying in a car crash are one to two percent.

Are you afraid of heights? It's the second most reported fear. Your chance of being injured by falling, jumping, or being pushed from a high place is 1 in 65,092. The chance of having your identity stolen is 1 in 200. Do you fear being killed by a bolt of lightning? The odds of that happening are 1 in 2.3 million. You're much more likely to be struck by a meteorite—those lifetime odds are about 1 in 700,000.

How about dogs? They're bark really is worse than their bite: Your chance of suffering a dog bite is 1 in 137,694. On the other hand, your chance of being injured while mowing the lawn is 1 in 3,623. How about sharks? You're much more likely to be killed by your spouse (1 in 135,000) than a shark (1 in 300 million). Won't ride a roller coaster? If you have the patience to stand in the line, the chance of a roller coaster injury is 1 in 300 million. But if you play with fireworks on the Fourth of July, you're really playing with fire: the chance of injury is 1 in 20,000.