Hollow

A person or animal that concentrates on a task for so long that he only concentrates on it without deviation.

Without saying anything against it or complaining constantly about it, but still continue with this activity no matter how bad it is.

ey, you alright tim?

tim: yeah but the pay is bad ,its not fun anymore ,but well i gotta do what i gotta do.

why not change your job?sounds like you transform into a "hollow"

tim: nah, its fine ,f###, they gave me the night shift again

come on dude , i mean you could get something better .

etc....