I think you are correct, Andy: we should have a lot more good weeks than bad weeks or great weeks.
A good week for me is if I can go into the weekend not worrying too much about something, project or personal. If I can keep the gauge in this area, I'm pretty happy.
A great week is when I have a breakthrough, hit a major milestone, have a family experience, etc.
A bad week is if my wife is upset at me. That's also a bad week for the whole family, too. :-)