I'm subscribed to many threads here on the forums.
Any time I view a link from any notification email, all other threads think I have viewed them too. The think I've viewed them even when I have only read other threads on the forum, too.
So, say I'm subscribed to threads A and B.
I receive email notifications for both threads.
I view the notification for thread A, and click the link to view the thread. I'm taken to thread A at the location of the first unread post.
I read this thread for a while, then go back to my email and see that I now have 2 notifications for thread B. Following the link from either of these notifications takes me to thread B at a location much past the post I last read there. I then have to scroll back a bunch and try to find where I actually read to.
This can also happen if I don't read any notification at all, just view other threads on the forum.
Why does the forum think I've read threads that I haven't?