Embarrassing but true. All of it. But especially the part about smiling and listening. Kindness is usually met with kindness, and politeness goes a long way to make people treat you with equal regard.
I'm an old fashioned Dane from before the time when manners became passé in Denmark, which was at least 20 years before politeness went out of fashion in the US. Contrary to popular belief, Americans used to have at least as lovely, often better, manners - some still do - as any European.
Good manners are not stiff and off putting, they are about keeping everyone comfortable in any situation. Politeness is not fawning or patronizing, it is a show of respect for others. A polite person will almost always be treated well, whether good looking or not so good looking, because politeness is attractive, disarming and charming,
Good manners are like traffic rules: drive carefully, drive politely, drive courteously, drive defensively and know the rules. It is not at all fair not to teach children old fashioned good manners. It is like letting them out in traffic without teaching them any traffic rules.
Rudeness, ugly words and bad temper can make the prettiest person seem ugly, but they also make a less pretty person seem even uglier - life is not fair.

Jaye, you are very cute!!!!!!

politely,
birte