The worst part about a lack of common sense is, those afflicted feel they know all they need to know to debate anything they have even the faintest opinion on. No matter what you believe, who you are or where you come from, please learn real facts about something before you tell everyone you know what you think is true and they just accept it because they trust you. Word of mouth is in my opinion one of the most effective means of communicating an idea to a large audience. Maybe it won't happen overnight, but it's great advertisement. The problem with this in modern society is so many people will simply take what they hear and believe it, without a second thought to it. Because after all, we believe in crazy things like Angels, Ghosts, and Noah's Arc don't we? If someone tells you that the sandwich shop down the street has great meatball subs, that might cause you to make a decision to go and try their meatball subs when you otherwise wouldn't have. However if you find out from personal experience that the shop's meatball subs taste like vomit, you aren't going to still believe that lying person that told you they were great.
The problem here is different for different people. If I tell you a law is being passed that will limit the amount of gasoline a car-owner can purchase, how do you know that I am lying? You couldn't possibly know that I am lying unless you are a member of congress or you took the time to research current laws being passed. But who has the time to do that kind of research? What I told you doesn't sound completely crazy what with the "oil crisis" and all. Actually it sounds downright plausible to you, and since you can't be bothered to actually do some critical thinking and research, you might as well just accept it as truth and tell everyone you know. This is exactly what I'm talking about here, common sense is so uncommon. Nobody feels the need to know anything to be true for sure, if they hear it from a reliable source it must be true. What has happened to human logic and reasoning? It sometimes feels as if we are devolving as a species the capacities of the mind which enabled us to triumph over all other species in the first place. The world can be a lonely place sometimes when you feel like the only person with reasoning skills. That is not to say that I actually believe that to be true, it's just a disheartening feeling.