Dear raging vortex,

Something like that happened to me before. I would get hungry when I saw rust on metal. Later during routine lab tests I was diagnosed with anemia. The doctor prescribed an iron supplement. Rust is iron oxide. I wonder if somehow my body knew it needed iron when I saw rust. I have rusty pipes in my house and a year before I bought a water filter. What I didn't realize is that the rust in the water was helping keep me from being anemic. Maybe this is totally unrelated to the kind of thing you are describing though.

Sincerely yours, Yao Wen