Padlock on closed discussions

Why don't you put a lock icon on closed threads?

In this way, when you enter any section of the forum, you immediately see which ones have been closed.

Any thread older than one month shouldn't receive posts anyway. It's in the rules, considered "necroposting."
Aside that, I can't picture any normal user running into that sort of "issue" nearly often enough to require something like this, only those that seem to be farming post count by posting pointlessly everywhere.

Of course, it shouldn't, but that doesn't mean that a person can't express their opinion on whatever topic it is.
If you "really" want to avoid bringing a discussion back to the top, then give yourself a certain amount of time after which you close it so you avoid these situations.

You know how it is, we are human beings and as such we can make mistakes, I can also understand your rather obvious and very common conclusion.

Aside that, I don't really care if what I've suggested is ignored or taken into account.
It's just a little advice, nothing more.