Noun.
Etymology: repr. Greek κοινὴ αἴσθησις, Latin sensus commūnis, French sens commun.
Definition:
a. The endowment of natural intelligence possessed by rational beings; ordinary, normal or average understanding; the plain wisdom which is everyone's inheritance.
b. More emphatically: Good sound practical sense; combined tact and readiness in dealing with the every-day affairs of life; general sagacity.
(Source: Oxford English Dictionary Online)
I feel like there are a lot of people out there who would benefit from knowing this definition. Or really, even being aware of the concept.
People who could benefit:
Marketers
Politicians
Sales people
Children
Co-workers
This is not a full list obviously, but serious repeat offenders most in need of rehabilitation.
We all have off days sure, but generally when those of us who have mastered this skill have done something stupid, we recognize it quickly and apologize if it is in front of others or hide it and bury it in our memory if we are alone. This is the way it should be.
Do not revel in your stupidity. Do not flaunt it. DO NOT inflict it on those of us smarter than you, we become annoyed and often effectively passive aggressive. We will cause you to suffer in any way we know how; Social Darwinism at its best.
I do not suffer fools gladly and neither should you. Speak up for common sense! Explain it to those less fortunate to whom it is not a natural state of being.
And if nicely explaining and/or flash cards does not work: do your passive aggressive best.