It's very rare that I mark unread posts to read. There have been times when I had just so many I did mark as read. But not too many times.

I'm online as often as I can. I do try to read every post. I take my moderator responsibilities too seriously.
It's not such a task especially these days with a pretty low daily post count.
Besides which I'm just too nosey to give up

For those regular members with a mountain of posts it's better to 'mark as read' and then make a new start.
IMHO