Nope. It doesn't need to make any.
And I doubt oysters have goals, what with being mollusks and all.
But humans do, and they get to set what they are.
Generally speaking, a healthy person sets goals based on how satisfying the outcome is, for some reason or other. For some, that's satisfying to others, perhaps future generations, not to be realized in their lifetime (though the thought of that satisfaction is a driving force). For others it's more direct.
Perhaps the key here is thinking about what is being satisfied as the justification for the struggle. Because if you're just punishing yourself for the sake of punishment, there's probably better work you can be doing...
