False Endings and Indefinite Conversation

From Zanecorpwiki

After 20 years, I've finally realized what it is that makes talking to my mother so frustrating: every conversation has at least one and possibly an indefinite number of false endings. In the last conversation, there were three. Helen: "All right, that's all." Me: "Okay, then, talk to you later." Helen: "Scarlet [the dog]'s been sick." Later: Me: "Well, I'll see you tomorrow then." Helen: "What did you do for New Years?"

I never know whether a conversation is going to last 2 minutes or 20 minutes. She gives signals that the conversation is over, but then just keeps on talking. I can't stop a conversation myself since the normal, "Let's wind it up signals" are ignored, so I'm forced to either be rude or pre-announce a time limit. Neither of which I'm generally disposed to doing.