There are top 5 rules we follow daily without giving it a second thought.

But where did they come from?

#1). Shaking hands when meeting someone.

Handshakes have been used since the 5th century BC in Greece. It was a way to show strangers that you are not carrying a weapon and came with peace.


#2). Saying "bless you" after a sneeze.

Historically, sneeze were considered an omen from god's. During the bubonic plague pope Gregory the great urged people to respond with a blessing since sneezing could be an early symptom. Basically bestowing a good luck charm on those at risk.


#3). Saying "Please" and "Thank you".

In a hierarchical society saying please and thank you was the earliest way to express equality among the working class. Please sohort for "if you please" ,make the request a favor instead of an order. "Thank you" evolved from the phrase "much obliged" ,meaning I am in your debt. And by saying "you are welcome" or "no problem" you are stating that the debt is unnecessary.


#4). Driving on the right side of the road vs the left.

The easy answer is that after independence, The United States wanted to separate their customs from those of Britain. The long story is a bit more complicated... 

When Wagons were invented drivers sat on the left. This tracks back to the way they rode horses, since it is easier for right handed people to Mount horses on the left side. Wagons would drive to a right side of the road to make it easier for drivers to see other Wagons pass by UK royalty, however drove on the left side of the road to separate themselves from the rest. Soon after all UK cars were made to drive on the left side of the road.


#5). Tipping at a restaurant or bar.

Tip was initially a term used by criminals to describe illicit money exchanges. Later it grew to describe the money overnight guests left for their hosts as a "thank you". Soon after people universally did the same in coffee shops and restaurants but European countries get rid of the practice and raised the minimum wages instead.


These rules are so ingrained in our culture they are almost a reflex.