president obama argued, he planted a seed in me that i interpreted it too narrowly. that s included not just international law, but u.s. historical practice. and i went back and really thought about that. he made a compelling case, and i went back and have dug deeper, studied it. ultimately concluded he was right. what he had said, and i referenced that in my subsequent opinion, based on the arguments, i had gone back. it just like a replay official. i made the call in the original case, but went back and looked at it again carefully, studied it, and in fact concluded that he was right. so that was one example where and one of my opinions, pointed out that in a previous decision, i had under interpreted the scope of one statute. going a little bit further, which ones where the most difficult?