There are a few long-running threads I follow and occasionally post on. These threads I have marked to Watch so that I don't have to search for them every time I've closed down.
There are also a lot of threads I post on once or twice then never return to (unless I get notified that someone's mentioned me).
Given that all the threads I post on are in the Threads I'm On list, do they really need to be in the Threads I'm Watching list as well?
As things stand, to use the Watch feature I have to scroll through quite a lot of things I don't want any more.