"I could do it because I was strong in the Force...and because I had absolute faith in my right, my need to use that craft for a specific purpose.
But I doubt I could do it today. I'm no weaker in the Force, and I'm a lot more skilled... but today I'd know that my intended purpose was not a good one, and this knowledge would deny me the focus I needed then to perform that task.
So was I a Master then, or am I a Master now?"
He's referring to thread stickied at the top of this page:
http://www.killermovies.com/forums/f6/t636721.html
uhuh