This poster is on the wall of the tearoom at my department. It has a bizarrely apposite role in the iconography of my life. Quite what one's PhD might be for, or what value it might have, is often rather obscure. In my case, very often indeed. But the general panacea for these anxieties is some general thought of the form, "Of course it's not clear to you. But fear not! It is Good. Everyone thinks so!"
Which just makes me think of DDT.
Second, and assuredly more disturbingly, one of my professors (Dr X the fungi nut, not Prof Agent Smith) has likened me to the woman in this poster. Twice.