Common Sense Isn't That Common
What is common sense? Common sense is, by its root, some experiences that had been repeated again and again, until it's viewed as the norm. And what is science? Science is trying to disprove a hypothesis, and when cannot disprove, will temporarily become the truth. See the similarities in definition? So when it comes to science, when you disprove something, like Einstein proved that Newton's formula is just an approximation that isn't totally correct, or perhaps Pluto used to be a planet but was disproved against, or if you're someone aiming for healthy eating, what fad we have in the past isn't the fad we have today: as science growth, new nutritional diet keeps changing. So when you're looking at science, we understand that we need to keep up to date, rather than stay on the same place. That isn't quite true for the rest of humanity, at least, isn't what most people expect.
People want confirmity, people want static; people don't want hypothesis, people don't want dynamic: that's because it makes easy for the brain to learn something when it haven't learnt; but it's extremely difficult to relearn something that you already make it a "common sense". And with the malleability of science, that perhaps keeps changing (relatively) fast, it's no wonder that people can't keep catching up with so much other things they wish to focus on, and just doesn't have enough attention to continually keep up with the news. Me inclusive. But that isn't the topic: the topic is, by prefering static and confirmity, we make something that's originally "temporarily true" and "may change in the future" a "common sense", when it isn't common at all; and still subjecting to change.
Let's look at a story. You probably thought that short-sightedness is due to too long looking at screens, or at least something near like books, causing muscles to strain and become near-sightedness. However, more recent researches suggests that short-sightedness is caused by the lack of the hormone that signals our eyeball to stop growing. (View the video to not get confused by my statement). The hormone only grows with longer exposure to sunlight, and as you know, bookworms stay in the libraries, and people nowadays watch stuffs under the shed (of our roof), hence lacking the hormone. If we instead watch screens or read books under sun exposure, it'll fare better. (Of course, don't get dehydrated, don't fall sick, etc, "common sense").
Now, why do one brings this topic online? Cause most people are so into the common sense, that they thought their "common sense" are easily understood by other people, when it isn't. This is when "common sense" clashes. What one viewed as "common sense", you might view as "weird". Let's take an example: I'm living in Eastern countries, and it's viewed that wearing too little in public (just an underwear, with/without a bra depending on your gender) is liable of getting jailed or at least fined; which isn't really the case in quite a number of Western countries. While to us it sounds "common sense" that wearing too short in public is a bad thing, can easily lead to cultural shock, and isn't respectful; others might view as "huhhh???"
Another thing is an unwillingness to change, or you could call stubbornness, fixed mindset, etc. When someone tries to explain about what had changed since we last learn, someone unwilling to change probably view that as an attack to their inner self, to disprove their status, and to downplay them. Hence, viewing it as an attack, we normally goes into a defensive mode, to defend our cause rather than trying to understand what's new. "Huh, I have my own proof that I'm correct, you're wrong!" When replied "No, I'm sharing a fact to you.", encountered with "No, what you say is wrong."
In conclusion, "common sense" isn't that common after all. It's really just something that we keep experiencing that we treat it as something that's common. When what we experience is different from what other experience, we'll have a "common sense clash", and communications trying to clarify (or attack/defend the other person, if you're a bad communicator) the differences escalates difficulty. When some "common sense" is hold as saint, or by someone hypervigilant, a statement that disproves such common sense would be viewed as an attack to their "saint" or their "inner self", hence triggering defensive responses to eliminate all cause of uncertainty, be it murder/jailed (remember Copernicus? Galileo?) or avoidance. So, it's time to accept that common sense could change in the future, and we shall accept the new "common" sense as time goes.