Air conditioning: In 1929, Senator John Rankin said that chilly rooms were full of "Republican atmosphere, and it is enough to kill anybody if it continues." Well, Mr. Rankin, turns out you were wrong. The advent of air conditioning has actually reduced the number of heat-related fatalities significantly.

Where's Waldo: A child in Long Island once found a woman's partially exposed breast on a page of a popular "Where's Waldo?" book, and his overly concerned parents thought the image would corrupt his young mind. They were successful in getting it banned from the school library.

Writing letters: People in the late 1800s were concerned that promiscuous young ladies were writing scandalous letters to corrupt the minds of young men.

Dungeons and Dragons: After a while, mothers became concerned that their kids were spending too much time on this game, causing them to lose their jobs, their friends, and even their lives. While some people became so obsessed that things like this happened, those were extreme cases. It's just a game, after all.

Tomatoes: When the legendary "green tomato worms" started infesting tomatoes back in the 1800s, the fruits developed a bad reputation as being poisonous. In the end, neither the worms nor the tomatoes were poisonous.

Licking stamps: In the 1920s, people believed that postage stamps were full of bacteria that was harmful to humans. This strange idea didn't last long, because that theory was quickly proven wrong.

Public toilets: Some people still believe that you can contract STDs and other diseases from sitting on public toilets, even though it's been proven to be almost impossible.

Watching TV: Due to a factory error in the '60s, TVs were emitting 10 to 100,000 times the normal amount of radiation. That caused the public to go into a frenzy about becoming radiation monsters. That obviously never happened.

Dancing: A 1926 article claimed that a girl died while doing the "deadly" Charleston dance. Other articles claimed that the provocative nature of dancing would be the death of feminine modesty. All forms of dancing were considered scandalous at one point, but we all know that it's just fine.

Clothing: A scientist in 1901 claimed that nonporous clothing was extremely dangerous, because humans breathed through their lungs and their skin. While that is true, your poly-blend shirt won't kill you.

Women's sports: People in the 1920s believed that women who participated in sports were less desirable, which meant that they would never find husbands.

Public transportation: It was once believed that bacteria on public transit handrails was infectious enough to kill. While subway handles are pretty grimy, we'll live.

Gum: People really did use to believe that swallowing gum would lead to intestinal blockage. It's probably not good to make a habit of swallowing your gum, but have no fear — it won't hang out in your stomach for seven years.