It's been too long since I added another to my list of "Lowe's Laws of the Lab". They're something I came up with in graduate school, late one night in the lab. Looking back on them, I can tell I was in a bit of a bad mood when I put them together, but that doesn't narrow things down very much. I wasn't at my best for four or five years there, from what I can see.
Today's law is: You are in real trouble if someone knows more about your project than you do. That's a realization that hits people at some point in their graduate school career - preferably not much past the midpoint. It marks the transition from being a student to being a working scientist. After all, when you're still a student, other people are expected to know more about what you're doing than you do yourself; you're supposed to be learning from them.
But that has to change at some point. It's not that you suddenly get as smart or as experienced as the better grad students or post-docs in the group, let alone your PhD advisor. More talented people might be better at your project than you if they devoted all their time to it, but they're not doing that: you are. No, you get to where you know the ins and outs of your own project, your corner of the research world, better than anyone else. With that comes the realization that no one else is going to get your project done for you, and no one else is going to get you out of grad school. If you don't reach that level of involvement and expertise, something has gone wrong, and things will continue to go wrong for you.
That's because you need that experience if you go on to a further career in research. If you're going to be any good at your work, you have to be willing to become the expert on what you're doing, and not rely on others to have things figured out. Because what if they don't? This happens rather often, which is another valuable lesson that grad school is supposed to teach you. (Independent work isn't just for PhDs, either. Experienced Master's level employees at a drug company are expected to work more and more on their own as time goes on, too, and will be considered more valuable the more that they can do so).
I don't mean that it's a good thing to bull around the place, telling everyone that you know best what to do and to get out of the way. You never stop learning the research trade; anyone who thinks they've seen it all is mistaken. But I am saying that the opposite sort of behavior is a very bad sign. "What do you think about this?" is a fine question to ask people, but it should never shade over into "Tell me what to do". And "I don't know; that's his department" or "I never got around to understanding that part" are statements that should get any lab head or project leader removed from their position. If you don't know these things, who will?