There is a button "Active" somewhere below. It will show you threads that recently had replies.
for example if we had a thread 7 days ago, it's probably burried and you cannot find it.
But if someone responds on it today, it'll show on top of "active threads"
there is also a 'follow' button on each thread
this gives you an option to get a reminder on the page that there are other threads you 'followed' that have updates.