Why were diariy entries started with the words "Dear diary"?

Question

Why were diariy entries started with the words "Dear diary"?

Answer 1

Because its name is Diary  and is like if you are writting a letter, you ALWAYS say: i.e: Dear Uncle, Mom or someone's name.... in this case its your diary!

Answer 2

It seems logical.  People would write letters to Dear Mama, so when the only recipient was a diary...there you go.

I was hoping to find some web reference to, e.g.  Sally Bloggett -1722;  but the only references are recent pop culture.

Answer 3

I think it's to personify the diary as if it were a real person. When some people write in a diary they act as if someone is listening to let ideas flow more freely. Starting with dear diary also gets a train of thought going and the writer doesn't have to worry about starting their entry when they use "Dear diary" all the time.