hmmm...
By lost I mean in your own mind you feel another party made their point better than you and by here I mean on any HZ board.
Most often, I don't engage in argument precisely because someone else has already made my point better than I could. Beat to the punch, as it were.
Just at the moment, I can't think of one that doesn't fall into the category of "arguments walked away from", due to fatigue. I've yet to change my stand about an issue as a result of thrashing it out in the Zone... which, I like to think, means that I've refused to close my mind.