Yes, I know who he is. Although I had a much older account, which password I couldn't recover, because it's from the days when no email was necessary here, I frequent HN for years and that's why I care about this community as I spend a significant portion of my life in here.
We can sometimes help people regain old accounts with no email address in them. If you still want it, you're welcome to email us (hn@ycombinator.com) with the username and we'll look into it.