Ask HN: How much should you care about your work?

I used the term 'work' loosely here, but I guess it applies more to full time workers and startup founders - where money usually isn't the most important factor in job satisfaction. From the professional level, I really believe one should care enough about the work - it's a big and important part of your life, if you don't always think about how to do things better then what's the point? On the other hand, caring too much is dangerous - feelings will get hurt and you'll become frustrated quickly and frequently. Sometimes, you might simply not have enough energy to fight against questionable (or even unethical) decisions. So, dear HNers, what's your take on how to balance how much you should care about your work?