I'm currently reading a biography of Sylvia Plath, Red Comet: The Short Life and Blazing Art of Sylvia Plath by Heather Clark. I'll be reading it for quite some time yet for it's about a thousand pages long and I'm only up to her twentieth year when she was a student at Smith College. It is rich with the most minute details of Plath's life. She was a prolific journal keeper. She was extraordinarily explicit about her experiences. She maintained correspondences with several people who kept her letters and all of this material was available to Clark in writing her book.
I've never read very much of Plath's poetry. I did read her one novel, The Bell Jar, which I found fascinating. But of course, it was the poetry for which she was primarily famous. Clark makes reference to several of her poems in the text of her book. One that she particularly references is this one, "Lady Lazarus."
Throughout her early life, in her journals and correspondence Plath made frequent reference to suicide. It was obviously a thought that returned to her time and again and, tragically, she did eventually commit suicide in 1963 at age 30. "Lady Lazarus" is generally accepted to be an expression of her suicidal thoughts and impulses. She writes of attempts at suicide and says:
Sad. If only she could have seen that living is an art, too, a more complicated and difficult one than dying.