Thats an entirely subjective argument there green 
Sometimes when your sick, you can feel a little drain of energy (as in feeling weak, not as in someone cast an energy drain spell on you) before any real symptoms, like you pointed out show. However i'll agree with you, if you started having symptoms like that, you'd no somethings up. Im just saying if its just a single stat loss, some strength sapped away, it might not be immediately noticeable.
Your feeling a bit weak for a while, then the real symptoms come into play.

Sometimes when your sick, you can feel a little drain of energy (as in feeling weak, not as in someone cast an energy drain spell on you) before any real symptoms, like you pointed out show. However i'll agree with you, if you started having symptoms like that, you'd no somethings up. Im just saying if its just a single stat loss, some strength sapped away, it might not be immediately noticeable.
Your feeling a bit weak for a while, then the real symptoms come into play.