As put forth by the Second Splendid Truth:
One of the best ways to make yourself happy is to make other people happy;
One of the best ways to make other people is to be happy yourself.
Everyone accepts the Second Splendid Truth, Part A; the Second Splendid Truth, Part B often isn’t as clear to people.
But to focus on Part A here — how do you know if you’re making other people happy? What are some signs?