I scanned through the first few pages and couldn't find a thread with this question, if it's been asked and I missed it, I apologize.
So, I'm trying to find a game I was previously in but removed from my sticky list. Im not sure if it's been deleted yet but is there a way to find games I've been in but aren't on my list. Thank you for any help that can be provided.

Easy!  :)

User Preferences (upper left on your screen now) ==> Manage Games You Monitor ==> Are You Missing Any Games?

Thank you very much!

No problem.  If only all life's problems could be fixed that quick.

How does it know which games you wanted to remove and what was mistakenly removed?  Length of time since your last post in the game?

It doesn't know which games you did or did not want to remove, which is why it asks which you want to re-add.  It looks for games you are a member of and gives you an opt-in list of games to add back onto your list.