Common sense

people always say something is common sense.

• John said "2 Sin[x] Cos[x] = Sin[2 x]" is common sense.
• Mark said "Queen can go all direction, like a combination of Bishop and Castle" is a common sense.
• Mary said "Louis Vuitton is come from Paris and founded in 1854" is a common sense.
• my mother said she is a female is common sense.

we can see from above examples. "Common sense" means usual fact among some group. John's case refers to mathematicians. Mark's case refers to chess players. Mary's case refers to fashion freak or wiki -reader. my mother's case may be the truly "common sense" in common sense.

so, Common sense is not common as we though. due to the social gap, specialization/professional or education level. in HK, may be the 99% population covered common sense is the things were tough in kindergartens or P1. in China, may be somewhat different. for example, sitting all around is a common sense for mainlanders. washing hands after toilet is a common sense for HongKongers. Mother is female is a common sense for all world.

Common sense has a kind of level and professional. by investigate the level of common sense among people, we can check out our education system good or not. so, the TV game show- millionaires is a good show for knowing people level of common sense.

Next time, think before using "common sense", is it really common? if somebody use "common sense", don't afraid to ask back "what is common sense?". i bet he/she will be shame for don't knowing "common sense" as a common sense.