Eating a lot does not necessarily fill me up. I did not shake from hunger but from looking forward to having a full stomach later.

Why doesn't it fill you up? Hunger doesn't bother me either, I know my body resists and eventually pounces to its needs.
Headaches are a major concern for me, they just shoot down productivity.

Our expectations end up being our headaches.

A very much philosopher's mindset, btw 'I don't have any expectations, however it goes.