A French criminologist named Emile Locard came up with an idea he called Locard’s exchange Principle. It says that any person passing through a room will unknowingly leave something there and take something away.
That means any encounter we have with people today leaves us and them better or worse, but never the same. An exchange takes place.
Do you usually cause people to smile or frown? Is your conversation complimentary or crude, caring or caustic? Do people discern that your emphasis is on you or on others?
In every room in which you meet a person today, an exchange will happen. The real winners are persons who make others better for having met them.