Here’s a fact for you: Knowing more about sex is good for your sex life. But although sex is one of the most popular activities in the world (it originates back to, well, the beginning of mankind), it's also one of the most secretive. So, it’s only natural that countless myths have accumulated around the topic over the years. Some of them are outlandish and downright ridiculous (aphrodisiac green M&Ms, anyone?), but as crazy as they are, some myths are actually true. 

Here are six of the most common beliefs about sex. Can you figure out which ones are true and which ones are false?