@paulo-0 well making a topic as watching I think puts it into both unread and notifications, and if you visit the topic it will clear it from unread, and clear all notification for that topic (I forget if it still shows you a notification about something like someone up-voting a comment you made even if you visit the topic that notification was in).
I know you should have a notification that I mentioned you, and this will show as unread, so if you click the notification or the unread both will disappear.