Working on confidential material is cool because it’s an interesting concept/technology that (we think) no one has done or that no one has done it “our way”. On the other hand, you can’t talk to anyone about it.
At least I can talk to my Eclipse friends that work at IBM about it. If I couldn’t talk about it to any of my “casual” hacking friends (as in, not being able to talk to anyone about it outside of the “work” scope), I think I might’ve died already.