Compelled to create an account and comment after reading this great story and following comments. Gave me some perspective on Harvard for somebody who's never been there. Next time I see a Harvard Grad, I'll be sure to tell them how sorry I am.
Totally see your point about going to your discussion session run by the TA. I'd feel the same way in your position, but there's always something to learn from every life experience and am glad you found your lesson here as well. If they wanted you to have a discussion, you can go ahead and have it with your fellow classmates without and away from the TA.