When do you feel it is time to Abandon a Thread?

When it becomes a series of bickering posts between two users.

Any time it becomes a private conversation or just people posting a bunch of gifs.

When I am correct and the other knows it.

When it no longer possible to give the other person the benefit of the doubt about the possibility of his making any intellectual progress while continuing the thread.

probably when its done

The conversation becomes private, boring or argumentative.

The other person likes to get the last word/pic/gif and you're feeling generous.

One of AM's chuckleheads stops by to give unsolicited advice or demand proof of everything or in general wants to spew fart-gas in an attempt to prove their superior intellect so they don't have to think about how they haven't gotten laid in 20 years.