Courtesy means a lot to me as just a simple 'please' and 'thank you' can immediately brighten up one's glum day.Maybe something funny or something pleasant to the ear would be just enough to light up a big grin. :):):)

Courtesy must also be shown through your tone and actions, but most probably, a smile would do the trick! A glum 'thanks' will never ever help anyone in fact, you yourself may even feel more bored.

That is how amazing a little courtesy and a small smile can bring so much happiness to everyone's plain, dull, simle life!

Cheers!!!;)