Science vs. Belief: Well Known Facts that are Actually Wrong

We often do things because we learn from our parents and grandparents that it's true. Our outdated facts get replaced by scientific reason, but often the general public gets left out of the loop. 
So we continue on, believing things that aren't true and that may even harm us if acted upon. 
Reddit comes to the rescue to dispel some of the most commonly believed myths. While scrolling through the R/askreddit community, I found a thread asking users to share popular beliefs that have been proven false.
Here are some top responses.
Science vs. Belief: Well Known Facts that are Actually Wrong