Therapist

My therapist told me that a great way to let go of your anger is to write letters to people you hate and then burn them. I did that and I feel much better but I'm wondering... do I keep the letters?
A couple decades ago my therapist told me I had problems letting go of the past.
A Theory of Happiness
A Theory of Happiness A therapist has a theory that couples who make love once a day are the happiest. So he decides to test this theory. He convenes all the couples he can find at a special seminar. He then starts by asking the many people in the audience. “How many people here make love once a day?” Half the people raise their hands, each of them grinning widely. “Once a week?” A third of the audience members raise their hands, their grins a bit less vibrant. "How many of you make love once a month?” A few hands tepidly go up. No grins could be sighted. Then he asks, “OK, how about once a year?” To his shock, one man in the back jumps up and down, jubilantly waving his hands and whistling. The therapist is shocked - this man's reaction completely disproves his theory! “If you make love only once a year,” he asks, “why are you so happy?” The man shouts: "Today’s the day!”