Don't tell everyone everything

It's a human nature. If anyone has told us they are secret and then we have argument with that person in anger, we usually say all that in front of others. We break their trust. Anger towards someone can make you do things that you won't do to prove in your senses. So I believe. Why? To tell your secrets to everyone? Why? To let people take advantage of you or make fun of you? Keeping things to yourself?