In Federico Fellini's 8 1/2, the screenwriter (Daumier) at one point tells the director (Guido) something like, "If we only read those sayings on the chocolate wrappers, we would be saved so much pain." In other words, if we could keep in mind all the common sense knowledge that we have accumulated, we would be much better off. Of course, we can't. We can only keep so much of it in working memory at one time. This explains, I think, two phenomena.
First, it is inherently fun to be reminded of a common sense piece of wisdom. We get that feeling of, "Yes! Of course!" And, more importantly, that piece of wisdom is at the top of our consciousness—for a while. So, say we're feeling depressed because of some setback or bad situation and someone says, "This too shall pass," or "Tomorrow's another day." Trite? Yes. True? Yes. Common sense.
Second, a person can be smart but foolish, i.e., lacking in common sense. They can be very smart in the IQ sense, able to solve "convergent" problems. And yet they can do what we might call stupid things—failing to see a business opportunity, destroying a good relationship with a spouse, making errors of hubris. I saw this a lot at Microsoft, where most people are quite smart. But there are a lot of fools at Microsoft. A lot. It's interesting that, when I went to exec reviews with Gates, Ballmer, and other VPs, I never heard a lot of breakthrough thinking. But I did hear a lot of common sense, usually dished out caustically to extremely clever mid-level employees who had forgotten it.
Various pieces of common sense are continually "rediscovered." This is largely what the Self-Help section of the bookstore is about: repackaging common sense. Business books are largely the same way—they rarely say anything new. This does not mean that such books are stupid or a waste of time. Not at all. Why? Because reading one of these trite sort of books is largely a refresher of what we already knew but had forgotten temporarily.
Now, imagine a device which could, given a certain context, load into your memory the necessary common sense. Such a device exists. It's called a brain. It has common sense related to the way we grip physical reality—through perception of space, time, and causality (as Kant said)—and social reality, through folk psychology (broadly defined).
So the device exists, but it needs augmentation. At least mine does. On this blog, you'll find things I take to be common sense—which I need to be reminded of from time to time. I hope there is not a single original thought in this blog, because that will mean I'm doing something right. I also hope you find it entertaining and in some way useful.