The thing about poetry—one of the things about poetry—is that in general one does not follow growth and change through a poem. The poem is an essence. It captures perhaps a moment of violent change but it captures a moment, whereas the novel concerns itself with growth and change. As for the journals, you actually see the writer living out a life, which you don't in any of the other forms, not even the memoirs. In memoirs you are looking back. The memoir is an essence, like poetry. The challenge of the journal is that it is written on the pulse, and I don't allow myself to go back and change things afterwards, except for style. I don't expand later on. It's whatever I am able to write on the day about whatever is happening to me on that day. In the case of a memoir like Plant Dreaming Deep, I'm getting at the essence of five years of living alone in a house in a tiny village in New Hampshire, trying to pin down for myself what those five years had meant, what they had done to me, how I had changed. And that's very different from the journals.
— May Sarton, “The Art of Poetry No. 32,” The Paris Review