Is the phrase “A little courtesy never hurt anyone?” If so, it means be polite — even if it means a bit of sacrifice on your part. An example might be giving up your seat on public transportation for an elderly person or pregnant woman. Another might be saying please and thank you even if the person you’re talking to seems a bit rude.

Examples: “please pass the salt. Thank you.”

in a letter” Dear Uncle Fred, thank you very much for the birthday gift.

At a junction, waiting for another driver to go first.

At school standing up when the teacher comes in (this is a bit old-fashioned nowadays).

The point is that all this is free.Freely given, freely received

Hope this helps..