I was never really insane except upon occasions when my heart was touched.?

I've seen this quote everywhere on Tumblr, attributed to Edgar Allan Poe and I'm curious which story/poem/essay it's from. I've tried googling it and it just brings up endless amounts of Tumblrs featuring the quote. Does anyone know the source? I know that there have been quotes wrongfully attributed to certain famous figures in the past so that's why I'm curious to verify this quote.