Harry wants to say no, but remembers that he is trying to...if not be completely open about his history, at least talk a little more about it. Following his own advice, as it were.

What's the worst of it, Collins, that you would be willing to share? It might help to say it out loud.
I've tried, sir.
Well, you haven't tried with me.

"Our expedition was trapped in the pack ice for two winters," he says. "We finally abandoned ship to attempt to walk to safety. And there was a man—the caulker's mate on Terror—who fomented a mutiny." He stares down at the table, unable to look Alex in the eye. "There are many reasons I would not want to see that man or his closest allies again."