Why Do We Believe What We Believe?

I just saw an article claiming that drinking even up to six cups of coffee a day has many health benefits. It's all backed by scientific research, of course. This contradicts other articles I have read in the past claiming that coffee is dangerous to one's health; backed by scientific research, of course. Same for alcohol and many other things in life. Why should I believe any of them? Why do I or don't I?

I've never been to England, so why should I believe it exists? Why should I believe Adolph Hitler was a real person who actually lived? Some people claim that the Apollo moon shot was a Hollywood hoax, filmed in a studio. Why should I believe that? Who really shot JFK...if in fact he was really shot in the first place? If in fact he was a real person who was president. "Scientific research" has "proven" some wives' tales to be true, while others are false. Chicken noodle soup actually does help with a cold or flu, while children playing outside in cold weather doesn't actually cause them to catch cold; mothers calling them inside out of fear of catching cold causes them to share their germs because they're all in the house together is what causes them to catch cold. See I told you so. Did not. Did so.

And what about faith? The placebo affect is supposedly documented, that fake medicine can actually help with healing simply because the patient believes that it is going to do so. What about evolution of scientific theory? Each generation seems bent on proving the previous one wrong. Doctors used to pump antibiotics into people with the common cold. Later on, it was discovered that antibiotics don't work on viruses, and all the antibiotic use has created resistant strains of diseases.

Most of what we believe today will be laughed at at some point in the future by people who have proven us wrong. So why should I be judged for believing something contrary to the conventional wisdom of the day when I know it will be proven wrong sometime in the future? Why am I even writing about this?