My comment mentioned that the pain keeps you from thinking.

So, if the goal is something that you:

a) don't know how to achieve

b) are unlikely to learn how to achieve

c) have trouble thinking about anything due to the existence of it,

d) don't even agree with the goal,

e) your health does not suffer from not pursuing the goal

Then yes, taken together, it's obvious why goals meeting a-e are bad.