Under what circumstances would you become a cannibal?

First, is there any set of circumstances under which you would become a cannibal? For example, trapped in the Andes after a plane crash with nothing to eat, no hope of rescue, and frozen corpses all around you. Or offered a ritual portion of human meat while taking part in a traditional aboriginal funeral with a cannibal tradition. Or given the opportunity to try cloned human flesh grown in a vat. And so on.

Second, does your answer change if the method of eating human changes? For example, if the meat is undetectable as part of a larger dish? Or if you somehow gained the ability to swallow a body whole like a snake? Or if it was a teeny tiny person the size of your thumb you could just pop in your mouth like a french fry?