Auto Yeah Mode
When someone is telling a story and you really dont give a fuck, but to be nice you go into Auto Yeah Mode by countering there sentences with the word yeah. Also you can mix it up with a "I bet" or a "Really" to assure them you still give two shits.
Grandma: See back then went didnt have air conditioners...
You: Yeah...
Grandma: You could just leave your doors unlocked too.
You: Yeah....I Bet
Grandma: You could understand what they were singing.
You: Yeah....
Brother: Hey dipshit. what did she just say? are you in Auto Yeah Mode?