Manners for the 21st century: We all have manners, either good or bad, providing others with a first impression and ideas about the kind of person you are - polite or rude.
Good manners are an excellent way to distinguish oneself from a crowd of impolite and otherwise disrespectful people to an employer, boyfriend, girlfriend, boyfriend's or girlfriend's parents, etc.
Good manners stipulate that you treat others the way you would like to be treated - with respect.
Respect for others is vital to getting along with people generally. To be a civil society we must embrace the concept of the dignity of others, and regard them with appropriate respect, including good manners.
A few simple points: In a movie theater, concert hall or other place where people paid money to listen to something other than you, you should be quiet.
Cellphones and other electronic devices should be turned off in these venues.
Concerning table manners: knowing what fork to use is far less important than the one inviolable rule: Do not talk with your mouth full.
Keep your mouth closed while chewing. Your mouth should be covered with your hand when yawning.
Men wearing hats should remove them upon coming indoors.
"Please," "thank you" and "you are welcome" are polite expressions of good manners.
"Not a problem" is not an appropriate response to someone who thanks you.
Females of the human species are not "guys." While the term "guys" has become unisex in gender in common usage, a guy remains a male.
In school, the workplace, in social relations, throughout life, good manners will have a good return.