Haha, I think it is called getting "sheng mu"in cantonese (clear sighted). I used to be a "yes" woman in the past too but now, no more. Especially not in work. To me, working efficiently is more important than taking on endless projects just because someone asked for "help". In my previous company, I used to be a "yes" woman to everybody but towards the end, I became "No, no, no" even to my boss and he actually appreciated me for that cuz I will pour cold water on his wild ideas and let him see the "cons" of it instead of saying I'll do it to everything he asked.