A Lost Art
Letters are by nature thoughtful. First you think about the person you are writing to, and we all like to be remembered. Their face comes to mind, their likes and dislikes. Memories of good and bad times bring them close. You begin to write. You write things you know they will be interested in, you share parts of your life, your feelings, your beliefs. A letter is so much more then "Hi. How are You." It is a connection between two minds.
Because a letter is a thought process and we know it is a permanent copy of our thoughts we are, or should be, more careful of what we say. By using words to recreate our thoughts we must first clarify, in our own mind, exactly what we mean. This increases our insightfulness, it makes us evaluate our own thought process. It gives time to reconsider our ideas. (I've had some that looked pretty silly when I wrote them down, but that's what the round file is for.) Always reread what you write before sharing.
Possibly as far back as 6 centuries BC letters were written. It was, of course, the only viable means of communication between people in different locations. History, religion, politics, and daily life have been chronicled from personal letters. On an individual level a letter becomes a part of our personal history. A chronicle of our lives shared with those we hold nearest and dearest.
That is the thrill of a letter. You cared enough to think of me and write.