It may be a stupid question on this site, but it is somewhat bothering me:
WARNING: containing strong language.
In the movie Pulp Fiction, the character Marsellus Wallace says to Butch:
You see, this profession is filled to the brim with unrealistic motherfuckers. Motherfuckers who thought their ass would age like wine. If you mean it turns to vinegar, it does. If you mean it gets better with age, it don't.
Clearly, it refers to their ass, then what does their ass refer to? Does it just refer to unrealistic motherfuckers? If it does, then for the last two lines, will it be equivalent to say:
If you mean they (motherduckers) turn to vinegar, they do. If you mean they get better with age, it don't.
Or, is it the case that only an "ass" could turn to vinegar, but a human can't...?