One of my favorite oxymoronic statements is, “Common sense is not common.” There is even a Wikipedia essay on the concept. I was immediately reminded of the statement after reading a few comments on a reddit post showing a dryer lint trap that hadn’t been emptied in quite a while. A few of the comments asked a simple question, “How could this person not know to check the lint trap!?”
Think about all of the knowledge you’ve acquired that you probably take for granted:
Some of these lessons we learn from our parents and peers. Others we learn after something goes wrong—car engine seizes, pipes burst. Just this week I learned something that, in hindsight, makes complete sense. My bicycle tire burst (probably after hitting a pothole). The mechanic immediately, based on the snake bite pattern of the hole, that I don’t regularly inflate my tires. I simply didn’t know to do so on a regular basis. I would simply wait until the felt low and re-inflate. I’ve ridden bicycles since I was six. I’ve owned my current bicycle for about ten years. I’ve probably busted my inner tube in this manner at least six times. At no point until Thursday has anyone ever offered the simple advice of inflating my tires on a weekly basis.
The next time you find yourself about to say something along the lines of, “You’ve gotta be stupid not to know…,” remember that common sense is not common. Also, here is an XKCD for good measure. In the spirit of spreading (relatively) common sense, XKCD comics also include a bit of extra text that is visible when you hover your mouse cursor over the image. I've included it as a caption for mobile/table viewers.