That makes sense...

I've had occasion to visit, see some posts that were flagged to read, read some, responded to some, etc... and either went to another forum, or came back later, to find, sometimes these flagged posts unread still, or, not flagged, like I had read them...

I was wondering what was making them "stick" sometimes, and other times, not "stick", time based, makes sense... Cause sometimes I can leave the site completely, come back, and the unread posts are still unread, and other times, they get marked that they have been read... I wasn't really putting much thinking into "why" this was happening, and the "flip-flop" way it seemed to decide this, but, looking at it with this knowledge, it makes more "programatical" logical sense, that it is being done by time, and I agree, the database would get "way" out of hand if it needed to keep track of this information... Considering I can come in here, and find a whole screenfull of unread posts from the last time I visited, if it didnt clean-up on its own, I could have five, or six, of these screens to go through, on an "extended" away.