I first heard about the Biochemical Pathways poster in an unusual and enthralling book that I found while browsing the stacks in college — probably the only book I ever truly stumbled upon. It was called What is Thought?, by Eric Baum. Baum was enamored of the poster, and I felt I had discovered a well-kept secret. Years later, I wrote to Roche, the company that publishes it, pretending to be a grad student. They sent it to me for free. I had it framed, and it’s hanging now in my living room. ¶ I like it because it is magnificently complicated. It looks like the blueprint the aliens sent to Earth in Contact. And yet it isn’t nonsense. It’s a picture of decades worth of hard-earned knowledge about the natural world. I didn’t fall in love with biology until long after school, and I still know almost nothing about it. I like looking at this poster and being bewildered. But I hope someday to understand it — in the big picture and in the details.