I don't think you have to become stilted or act like a lawyer, or whatever you want to call it just because you're in law school now. I just think that if you're going to be entering a profession where success is predicated upon being articulate in how you communicate, the time you spend in training (i.e. law school) is a good time to be working out those little kinks in your speech. I don't really use like, but I do say "you know" alot. That's my kink to work out. I think it's a stutter in my thought process that I fill with "you know". Some people fill their stutter with "like". Others fill it with "um". Sometimes, in class, I count peoples' likes and it gets ridiculous when I'm counting 25 or 30 of them in someones question or comment.
It's not about acting like a lawyer all the time. It's about knowing the difference and when to turn it on and off.