The line you use when your friend is rambling on about bullshit
you don't care about and they lack the social awareness to
shut the fuck up, so you say the bare minimum to sound engaged.
Frequently but not always, the line has to be used when interacting with one specific person that thinks the drama in their life is
interesting to everyone around them. These tend to be the same people who use speakerphone in public and blast music in their cars because they assume the world revolves around them.