Some people believe only what they want to believe, as is depicted above. They are usually older and set in their ways. There's some truth to the saying "You can't teach an old dog new tricks". They use personal experience/opinion and throw out any scientifically backed data. Smart people use a combination of the two to come to a reasonable conclusion.
This is the internet, where when you ask a question you never know what kind of answer you'll get. Some respond with data backed by sources, while some respond with hearsay and delusional conspiracy theories. Take your pick.