How does the author compare herself to Langston Hughes?

From the text:

"Langston Hughes wrote in his autobiography that when he was sad, he wrote his best poems. When he was happy, he didn’t write anything. This is true of me, where poems are concerned. When I am happy (or neither happy nor sad), I write essays, short stories, and novels. Poems—even happy ones—emerge from an accumulation of sadness…."