I also got an alert about this post here, so I just assumed it was for this thread, it's really quite simple. I think i'll see how high I can get it before I fuck it up.
There are trophies/achievements too. Maybe you get one for having 100 unchecked alerts? Or maybe 1000?
But the way he said it, to me, seemed like he was saying "If I hadn't gotten an alert about this thread, I wouldn't have known that I had gotten an alert about this thread."