Know some law students here at OU through my son -- confidence they do not lack. :)
Yes, confidence is not a problem, but that's not to say there aren't problems!
One thing I say about many of the young adults in our best colleges and universities, as well as our law schools (of course, our Best & Brightest) is that they have a strange combination of exagerated self esteem, misplaced self confidence, and almost no genuine self assurance.
This is compounded by the fact that most of them 'don't know what they don't know.' That is, they will be cavalier and confrontational about matters of constitutional rights, for example, and yet show an almost profound ignorance of history, relevant historical documents (like the Federalist Papers), and in many cases even the text itself. This doesn't stop them from having a very loud and strong opinion.
What they lack in actual knowledge, they are very quick & willing to replace with things that they think they know but in fact, don't know. In fact, they seem to think that things they make up (sloppily) should have equal (or more) impact and weight than more established things.
The saddest part about this is, of course, that I think I can remember a time when I resembled those remarks. ;-)