Could you post a screenshot of what you mean?
Because if you did hit subscribe, it turns into unsubscribe. (as in no longer getting emails).

Or do you mean you don't want to get notifications on the website? Then you gotta hit the "Stop Watching" action.

There are threads I get notifications from just because I posted in the thread once. (Threads like What was your name on IMDb). Now every time somebody posts to that thread I get a notification. When I click on the notification to go to that thread, on that thread's page, Subscribe is listed on the left, not Unsubscribe. I would like to be able to click something RIGHT THEN, while I am on the thread's page, to stop getting notifications about that thread.

I am guessing you are saying notifications are different from Subscribing? If so, a. why? and b. Could I get something in the sidebar to turn off Notifications for a thread I am currently visiting?

I know I could set my overall preference to not turn on notifications automatically for threads I post in, But I DO usually want notifications for movie/tv/actor threads I have posted in.

I am guessing you are saying notifications are different from Subscribing? If so, a. why? and b. Could I get something in the sidebar to turn off Notifications for a thread I am currently visiting?

Yes, that's what the "Stop Watching" function/action is for, it's listed here in the sidebar, see this screenshot;
http://prntscr.com/ek1dff

You have to click that after you responded to a page and it refreshes.

Thanks. To me the gray font implied disabled/ghosted options. Guess not. That worked.